290 44 3MB
English Pages 190
STUDENT FILMMAKER'S HANDBOOK
TO THE STUDENT FILMMAKER The Student Filmaker's Handbook is a compilation of i nformation available in many different Kodak publications. It is a resource for you to use as you pursue a career in this most exciting of industries. It will interest you to know that you are entering the film industry at one of its most exciting and dynamic times. Technological innovations recently announced and those just around the corner guarantee that FILM will be a fascinating career far into the next century. Silver halide technology, the bedrock of film manufacturing, is moving ahead each year with new KODAK TGRAIN® Emulsions and new and improved color dye systems. Our scientists assure us that they will be able to improve the quality of film many times over in the next few years. What that means for you is that you will be recording sharper and more accurate color images than you have ever seen before. Those images will be manipulated in many new ways. HDTV (High Definition Television) is on the horizon and just beyond that is the whole new world of digital transmission of images over optical fiber networks. Eastman Kodak Company has recently demonstrated a new CCD HDTVTelecine and a High Resolution Electronic Intermediate System which will bridge the gap between electronic and silver halide technologies. And that is just the beginning. The good news for you is that your productions on film will be recorded on the one worldwide production standard. Wherever your work takes you, film will be the standard for motion picture image production. And what's more, you will have recorded your program on the highest resolution, brightest and most accurate color medium in the world. No other technology offers the quality of a film image; and remember, that quality is going to improve in the years ahead. So, welcome to the motion picture industry. I hope you will find this book useful, and I hope you will look upon Eastman Kodak Company as a source of quality products and technical support now and in the future. Sincerely,
n 0. K JULAA^— P0H nt/vvA_\, HenriDominique Petit Vice President and General Manager Motion Picture and Television Imaging Eastman Kodak Company
The Kodak Worldwide Student Program of the Motion Picture and Television Products Division gratefully acknowledges the contributions of BENJAMIN A. LUCCITTI for the publication of THE STUDENT FILMMAKER'S HANDBOOK
©Eastman Kodak Company, 1990, 1991 Second Edition, 1995 printing
TABLE OF CONTENTS Page INTRODUCTION
1
WHICH FILM SHOULD I USE
7
ANATOMY OF A DATA SHEET Film Types, Names, and Numbers Film Descriptions Negative Camera Films Exposure Information Exposure Index Exposure Latitude Illumination (Incident Light) Table Lighting Contrast Ratios Reciprocity Characteristics Filter Factors Color Balance Printing Conditions
8 8 13 13 13 13 14 14 14 15 16 16 17
SENSITOMETRIC A ND I MAGE S TRUCTURE D ATA Understanding Sensitometric Information Characteristic Curves General Curve Regions Curve Values Color Sensitivity and Spectral Sensitivity SpectralDyeDensity Curves Image Structure ModulationTransfer Curve Graininess and Granularity Measuring RMS Granularity Factors That Affect Graininess Granularity and Color Materials Some Practical Effects of Graininess and Granularity Resolving Power
18 18 20 23 24 27 29 31 31 33 35 37 37 37 38
PHYSICAL CHARACTERISTICS Film Base Antihalation Backing Edge Numbers Dimensional Change Characteristics Temporary Size Change Moisture Temperature Rates of Temporary Change Swell During Processing Permanent Size Change Raw Stock Shrinkage Processing Shrinkage Aging Shrinkage Other Physical Characteristics Curl Buckling and Fluting
40 40 40 41 45 45 45 46 46 46 47 47 47 47 48 48 48
STORAGE OF RAW AND EXPOSED FILM Raw Stock in Original Package Temperature Radiation Gases and Vapors Relative Humidity Handling Unprocessed Film before and after Exposure General Concerns Temperature Gases and Radiation Relative Humidity Handling
50 50 50 50 51 51 51 52 52 52 52 52 52
ROLLS AVAILABLE
53
CORES AND SPOOLS
54
WINDING
56
PERFORATIONS Sizes and Shapes Perforation Types 35 mm and 60 mm End Use 16 mm End Use Optimum Pitch for Printing Projection Print Aspect Ratios
57 57 60 60 60 61 61
FILM IDENTIFICATION Unprocessed Film How to Read a Film Can Label Processed Film Know Your Films Test Exposures To Provide a Reference Point For Locations with Unfamiliar Lighting To Establish a Reference with You and Your Laboratory To Evaluate Specific EndUse Appearance To Determine the "Look" of the Finished Job To Check Specific Color Reproduction
63 63 64 65 65 65 66 67 68 68 68 68
FILTRATION Filters Useful with All Camera Films Polarizing Filters Neutral Density Filters Filters for BlackandWhite Films Correction Filters Contrast Filters Haze Filters Filters for Color Films Selecting Filters for Correcting Color Temperature Light Source Conversion with Filters Light Balancing Filters Conversion Filters Limits to Color Temperature Measurement UltravioletAbsorbing and HazeCutting Filters Color Compensating Filters for Color Correction Combining Color Compensating Filters Exposure Allowance for Filters Filters for Color Printing
71 72 72 73 74 74 74 75 75 76 78 79 80 80 80 83 83 84 85
MOTIONPICTURE SOUND RECORDING A Brief History of Sound Magnetic and Photographic Sound Photographic Tracks Basics of Photographic Sound Photographic SoundTrack Reproduction
86 86 90 90 91 92
PROJECTION Handling and Inspection of MotionPicture Prints Common Causes of Abrasion and Wear Excessive Tension Misalignment of Film in the Projector Creased Edges RunOffs and Roping Abrasion and Dirt Cleaning MotionPicture Prints
93 93 93 93 94 94 94 94 95
DEALING WITH A MOTIONPICTURE LABORATORY Tips on Selecting a Laboratory Laboratory Services: A WalkThrough
96 96 98
MOTIONPICTURE LABORATORY OPERATIONS Processing Equipment Construction of Containers Transport Design Access Time Time and Temperature Agitation Mechanical Specifications Process Control
102 102 102 102 103 104 104 105 105
MARKETING A FILM Film as a Business Tool Potential Clients Client's Communication Requirements Reaching Agreement on Need for Film
107 107 108 110 110
DISTRIBUTION AND PROMOTION General Market Considerations Educational Special Interest Broadcast Television Cable Television Vacation Resorts Film Ingredients Running Time Professional Versus Industrial Talent Film Content Distributor Services Promotional Ideas Print Inventory Supporting Materials Film Maintenance
113 114 114 115 115 115 116 116 116 116 117 117 117 117 118 118
GLOSSARY OF MOTIONPICTURE TERMS...................................... 119
WHICH FILM SHOULD I USE Before selecting a specific film or films, you, the producer, and the director, will have to answer a number of basic technical and aesthetic questions about the entire production. The answers you provide will help greatly in the selection of the films that will best translate your concepts into moving pictures on a screen that convey your intended message accurately, completely, and effectively. You should consider the following factors because they directly affect your choice: • Anticipated release format. Will the finished prints be 35 mm or 16 mm? Shooting a 16 mm camera film to produce 35 mm release prints will involve some sacrifice in image quality. • Number of finished prints needed. If you need only one and you need it fast, a reversal film designed for direct projection will be ideal. If you are producing several prints, the camera film should be selected with an eye toward the economics of the various film printing systems. • The finished form of the picture. Should the finished film be in color or in blackandwhite? The aesthetic impact of blackandwhite film is distinctly different from that of color. What feeling should the film convey? The sharp distinctions in hue and density provided by a color film image can convey more information than the same image composed of shades of gray. Filmmakers should not assume, however, that color is always more interesting, or that black and white is always less expensive. Should the film be silent or should it have sound? A sound track can help to focus and direct a viewer's attention to the message. Answers to these questions depend on the purpose and audience for the film. • Type of lighting and exposure index. Will the subject be filmed indoors or out? Can you control the light? Some films are especially designed for low levels of light or for sensitivity at particular bands of the spectrum. All films are balanced for particular kinds of lighting. Will your film give you an accurate record of the colors in the scene if you make the motion picture only in the light available to you? • Type of filtration needed. If you have to use several filters to compensate for uncontrolled elements in the scene or in the lighting, will the film be fast (sensitive) enough to record a highquality image? • Type of processing and printing facilities available. Few labs process all types of film. If your nearby laboratory processes only color film, you may have to send your blackandwhite film to an outoftown lab. This situation can be especially timeconsuming if the film requires editing and must be shuttled back and forth several times. You can avoid much anxiety by getting to know the personnel at the laboratories that process your films and explaining your special needs to them. It may be worthwhile to select films that can be processed by a laboratory directly familiar with your needs.
ANATOMY OF A DATA SHEET Kodak's film data sheets are the best source for technical information about KODAK and EASTMAN Motion Picture Films. Each data sheet consists of one or more pages of detailed technical information for a particular film. These sheets provide useful information for the careful and knowledgeable reader. In the discussion of professional motion picture films that follows, we are using that form of a Film Data Sheet as a road map. The next four pages illustrate a data sheet for a hypothetical film that can be used in every stage of motion picture work. A real data sheet would obviously have fewer entriescamera film data sheet, for example, does not contain paragraphs titled "Printing Conditions" because printing conditions are only relevant to laboratory and print films. The large circles on the hypothetical data sheet illustration that is shown on the next few pages contain page numbers referring you to the beginning of a discussion on that specific topic. For example, the data sheet has a on the section "exposure indexes." If you go to page 13 and find the and the heading "Exposure Index," you can read about that topic. Each number on the data sheet will refer you to that section in the text. A single free copy of any film data sheet is available from Eastman Kodak Company, Dept. 412L, Rochester, NY 146500532.
Film Types, Names, and Numbers
and
Film productionfrom recording motion with a camera to projecting the image on a screen or cathoderay tubeoften involves three different kinds of film. Camera film is used to record the original scene. Many kinds of camera films are available for the many conditions under which subjects often must be filmed, for the special effects the cinematographer wants to produce, and for the processing and projection requirements of the job. Once the film has been edited from a workprint, laboratory films are used to produce the intermediate stages needed in the lab for special effects, titling, etc. Using intermediates also protects your valuable, original footage from potential damage during the printing process. Print film, on the other hand, is used to print both the first workprint and as many copies as needed of the final edited version of the project. People in the photographic industry generally refer to films by number (5248, for example) rather than by name (EASTMAN Color Negative II Film, in this case). Thus, the fourdigit number is more prominently displayed on the film data sheet than the name. The first of the four digits indicates the size or "gauge" of the film. When the first digit is 5, the film is 35 mm or wider; a 7, on the other hand, indicates a 16 mm film or a film that will be slit down to these narrower gauges after processing. When a film is available in both the 16 mm and 35 mm widths, both the 7000 and 5000 series of digits appear on the data sheet.
9
10
11
12
The name also indicates properties of the film. KODAK EKTACHROME Film indicates a reversal color film. Panchromatic and orthochromatic refer to the lightsensitivity range of the film. Most film names are self descriptive. The important thing to remember about the name and number is to use both accurately when ordering film or film date sheets.
Film Descriptions Under the heading General Properties on a typical data sheet, there will always be a brief description of the overall characteristics of the film. The paragraphs that follow describe each of the KODAK and EASTMAN Motion Picture Films currently available and are similar in coverage to the paragraphs found on each film date sheet.
Negative Camera Films Camera films are available in two general types: negative and reversal. Negative film produces an image that must be printed on another stock for final viewing. Since at least one intermediate stage is usually produced to protect the original footage, negative camera film is an efficient choice when significant editing and special effects are planned. Printing techniques for negativepositive film systems are very sophisticated and highly flexible; hence, negative film is especially appropriate for complex special effects. All negative films can go through several print generations without pronounced contrast buildup.
Exposure Information Film date sheets for camera films give exposure information under these headings: Film Exposure Indexes, Illumination Table, Lighting Contrast Ratios, Reciprocity Characteristics, and Filter Factors (blackandwhite film) or Color Balance (color films). Explanations of each of these elements are explained on the following few pages. Exposure Index The film Exposure Index (EI) is a measurement of film speed that can be used with an exposure meter to determine the aperture needed for specific lighting conditions. The indexes reported on film date sheets for EASTMAN and KODAK Motion Picture Films are based on practical picture tests but make allowance for some normal variations in equipment and film that will be used for the production. There are many variables for a single exposure. Individual cameras, lights, and meters are all different (lenses are often calibrated in Tstops). Coatings on lenses affect the amount of light that strikes the emulsion. The actual shutter speeds and fnumbers of a camera and those marked on it sometimes differ. Particular film emulsions have unique properties. Camera techniques can also affect exposure. All of these variables can combine to make a real difference between the recommended exposure and the optimum exposure for specific conditions and equipment. Therefore, you should test several combinations
13
of camera, film, and equipment to find the exposures that produce the best results. Data sheet Exposure Index figures are applicable to meters marked for ISO speeds and are used as a starting point for an exposure series. When it comes to measuring light, there are three kinds of exposure meters: The averaging reflection meter and the reflection spot meter are most useful for daylight exposures while the incident exposure meter is designed for indoor work with incandescent illuminations. Detailed directions for using all three are given in KODAK Pocket Photoguide, KODAK Publication No. AR21). The two reflection meters are sometimes used with the KODAK Gray Card. One side of the card has a neutral 18percent reflection which can be used indoors to aid in measuring the average reflection for a typical subject. You can also use this side of the card outdoors by increasing the exposure 1/2 stop above the calculated exposure. The other side of the card has 90percent reflection for use at low light levels. The use of this card and appropriate adjustments for aperture and exposure time is covered in KODAK Gray Cards, KODAK Publication No. R27. Exposure Latitude Exposure latitude is the range between overexposure and underexposure within which a film will still produce usable images. As the luminance ratio (the range from black to white) decreases, the exposure latitude increases. For example, on overcast days the range from darkest to lightest narrows, increases the apparent exposure latitude. On the other hand, the exposure latitude decreases when the film is recording subjects with highluminance ratios such as black trees against a sunlit, snowy field. Illumination (Incident Light) Table When the illumination is very low or when you cannot make reflectedlight measurements conveniently, use an incidentlight meter can be used to read the illumination directly in footcandles (lux). Note: Lux is the term used to describe the intensity of the exposing light in the current international standards for determining film speed. Most existing incidentlight meter scales are still marked in footcandles. A footcandle is approximately equal to 1/10 metrecandle or lux. Lighting Contrast Ratios When using artificial light sources to illuminate a subject, you can determine a ratio between the relative intensity of the key light and the fill lights. First, measure the intensity of light at the subject under both the key and fill lighting. Then measure the intensity of the fill light alone. The ratio of the intensities of the combined key light and fill lights to the fill light alone, measured at the subjects, is known as the lighting ratio. Except for dramatic or special effects, the generally accepted ratio for color photography is 2 to 1 or 3 to 1. If duplicate prints of the camera film are needed, the ratio should seldom exceed 3 to 1. For example, if the combined main light and fill light on a scene produce a meter reading of 14
6000 footcandles at the highlight areas and 1000 footcandles in the shadow areas, the ratio is 6 to 1. The shadow areas should be illuminated to give a reading of at least 2000 and preferably 3000 footcandles to bring the lighting ratio within the permissible range.
Lighting contrast ratio 2:1
Lighting contrast ratio 5:1
Figure 1
Reciprocity Characteristics Reciprocity refers to the relationship between light intensity (illuminance) and exposure time with respect to the total amount of exposure received by the film. According to "The Reciprocity Law," the amount of exposure (H) received by the film equals the illuminance (E) of the light striking the film multiplied by the exposure time (t). In practice, any film has its maximum sensitivity at a particular exposure (i.e., normal exposure at the film's rated exposure index). This sensitivity varies with the exposure time and illumination level. This variation is called "reciprocity effect." Within a reasonable range of illumination levels and exposure times, the film produces a good image. At extreme illumination levels or exposure times, the effective sensitivity of the film is lowered, so that predicted increases in exposure time to compensate for low illumination or increases in illumination to compensate for short exposure time fail to produce adequate exposure. This condition is called "Reciprocity Law Failure" because the Reciprocity Law fails to describe the film sensitivity at very fast and very slow exposures. The Reciprocity Law usually applies quite well for exposure times of 1/5 second to 1/000 second for blackandwhite films. Above and below these speeds, blackandwhite films are subject to reciprocity failure but their wide exposure latitude usually compensates for the effective loss of film speed. When the law does not hold, the symptoms are underexposure and change in contrast. For color films, the photographer
15
must compensate for both film speed and color balance changes because the speed change may be different for each of the three emulsion layers. However, contrast changes cannot be compensated for or contrast mismatch can occur. Filter Factors Since a filter absorbs part of the light that would otherwise fall on the film, you must increase the exposure when you use a filter. The filter factor is the multiple by which an exposure is increased for a specific filter with a particular film. This factor depends principally upon the absorption characteristics of the filter, the spectral sensitivity of the film emulsion, and the spectral composition of the light falling on the subject. Conversion of Filter Factors to Exposure Increase in Stops
Published filter factors apply strictly to the specific lighting conditions under which the measurements were made, so it may be desirable, especially for scientific and technical applications using reversal films, to determine the appropriate filter factor under actual working conditions. To determine a filter factor, place a subject with a neutralgray area, a KODAK Gray Card, or a photographic gray scale in the scene to be photographed. Shoot the scene without filtration. Then, with the filter or filter pack in place, shoot a series of exposures at 1/2stop intervals ranging from 2 stops under to 2 stops over the exposure determined using the published filter factor. Compare the (neutralgray) density of one frame in the unfiltered scene with the density of one frame in each one of the filter series, either visually or with a densitometer to find the filtered exposure that equals the unfiltered exposure in overall density. The filter factor is the ratio of the filtered exposure to the unfiltered exposure with equal densities. Filter Factor
= Exposure with filter Exposure without filter
Color Balance 0 Color balance relates to the color of a light source that a color film is designed to record without additional filtration. All laboratory and print films are balanced for the tungsten light sources used in printers, while camera films are nominally balanced for 5500 K daylight, 3200 K tungsten, or 3400 K tungsten exposure.
16
When filming under light sources different from those recommended, filtration over the camera lens or over the light source is required. Camera film data sheets contain startingpoint filter recommendations for the most common lighting sources: daylight, 3200 K tungsten, 3400 K tungsten, cool white fluorescent, deluxe coolwhite fluorescent, and MoleRichardson HI Arc lamps (both whiteflame and yyllowflame carbons). Printing Conditions A representative printer setup is described for each laboratory or print film. These printer setups should be read for comparison purposes and used only as a starting point The use of the Laboratory Aim Density (LAD) control method is recommended for determining optimum printing exposure.
17
SENSITOMETRIC AND IMAGESTRUCTURE DATA Sensitometry is the science of measuring the response of photographic emulsions to light. "Imagestructure" refers to the properties that determine how well the film can faithfully record detail. The appearance and utility of a photographic record are closely associated with the sensitometric and imagestructure characteristics of the film used to make that record. The ways in which a film is exposed, processed, and viewed affect the degree to which the film's sensitometric and imagestructure potential is realized. The age of unexposed film and the conditions under which it was stored also affect the sensitivity of the emulsion. Indeed, measurements of film characteristics made by particular processors using particular equipment and those reported on data sheets may differ slightly. Still, the information on the data sheet provides a useful basis for comparing films. When cinematographers need a high degree of control over the outcome, they should have the laboratory test the film they have chosen under conditions that match as nearly as possible those expected in practice.
Understanding Sensitometric Information Transmission density (D) is a measure of the lightcontrolling power of the silver or dye deposit in a film emulsion. In color films, the density of the cyan dye represents its controlling power to red light, that of magenta dye to green light, and that of yellow dye to blue light. Transmission density may be mathematically defined as the common logarithm (Log base 10) of the ratio of the light incident on processed film (Po) to the light transmitted by the film (Pt).
The measured value of the density depends on the spectral distribution of the exposing light, the spectral absorption of the film image, and the spectral sensitivity of the receptor. When the spectral sensitivity of the receptor approximates that of the human eye, the density is called visual density. When it approximates that of a duplicating or print stock, the condition is called printing density.
18
For practical purposes, transmission density is measured in two ways:
SAMPLE DENSITY
INTEGRATING SPHERE
TOTALLY DIFFUSE DENSITY
Figure 3
• Totally diffuse density (Figure 2) is determined by comparing all of the transmitted light with the incident light perpendicular to the film plane ("normal": incidence). The receptor is placed so that all of the transmitted light is collected and evaluated equally. This setup is analogous to the contact printer except that the receptor in the printer is film.
SPECULAR DENSITY
Figure 2
• Specular density (Figure 3)) is determined by comparing only the transmitted light that is perpendicular ("normal") to the film plane with the "normal" incident light, analogous to optical printing or projection. To simulate actual conditions of film use, totally diffuse density readings are routinely used when motionpicture films are to be contact printed onto positive print stock. Specular density readings are appropriate when a film is to be optically printed or directly projected. However, totally diffuse density measurements are accepted in the trade for routine control in both contact and optical printing of color films. Totally diffuse density and specular density are almost equivalent for color films because the scattering effect of the dyes is slight, unlike the effect of silver in blackandwhite emulsions. 19
Characteristic Curves A characteristic curve is a graph of the relationship between the amount of exposure given a film and its corresponding density after processing. The density values that produce the curve are measured on a film test strip that is exposed in a sensitometer under carefully controlled conditions and processed under equally controlled conditions. When a particular application requires precise information about the reactions of an emulsion to unusual lightfilming action in a parking lot illuminated by sodium vapor lights, for example, you can filter the exposing light in the sensitometer can be filtered to simulate that to which the film will actually be exposed. A specially constructed step tablet, consisting of a strip of film or glass containing a graduated series of neutral densities differing by a constant factor, is placed on the surface of the test strip to control the amount of exposure, the exposure time being held constant. The resulting range of densities in the test strip simulates most picturetaking situations, in which an object modulates the light over a wide range of illuminance, causing a range of exposures (different densities) on the film. After processing, the graduated densities on the processed test strip are measured with a densitometer. The amount of exposure (measured in lux*) received by each step on the test strip is multiplied by the exposure time (measured in seconds) to produce exposure values in units of luxseconds. The logarithms (base 10) of the exposure values (log H) are plotted on the horizontal scale of the graph and the corresponding densities are plotted on the vertical scale to produce the characteristic curve. This curve is also known as the sensitometric curve, the D Log H (or E) curve, or the H&D Hurter and Driffield) curve*. In the following table, the luxsec values are shown below the log exposure values. The equivalent transmittance and opacity values are shown to the left of the density values.
* One lux is the illumination produced by one standard candle from a distance of 1 meter. When a film is exposed for 1 second to a standard candle 1 meter distant, it receives 1 luxsec of exposure. * Zwick, D., "The Meaning of Numbers to Photographic Parameters." Journal of the Society of PhotoOptical Instrumentation Engineers, Volume 4 (1966), pages 205211.
20
The characteristic curve for a test film exposed and processed as described in the table is an absolute or real characteristic curve of a particular film processed in a particular manner. Sometimes it is necessary to establish that the values produced by one densitometer are comparable to those produced by another one. Status densitometry is used for this. Status densitometry refers to measurements made on a densitometer that conforms to a specified unfiltered spectral response (Dawson and Voglesong, Response Functions for Color Densitometry, PS&E Journal, Volume 17, No. 5 Sept/Oct 1973). When a set of carefully matched filters is used with such a densitometer, the term Status A densitometry is used. The densities of color positive materials (reversal, duplicating, and print) are measured by Status A densitometry. When a different set of carefully matched filters is incorporated in the densitometer, the term Status M densitometry is used. The densities of color preprint films (color negative, internegative, intermediate, lowcontrast reversal original, and reversal intermediate) are measured by Status M densitometry. (DAK Densitometer Filter Sets are purchased directly from the manufacturers of densitometers. For further information, contact the densitometer manufacturer.)
Figure 4
These illustrations show the relationship between subject luminance, negative den sity, and the characteristic curve. There is one stop difference in luminance between each of the points 2 to 10. Point 1 is a specular highlight which photographs as if it were about 2 stops brighter than point 2, which is a diffuse highlight. Point 9 is the tone to be reproduced just lighter than black. There are 7 stops difference between points 2 and 9. which is the typical range for normal luminance range subjects. Point 10 is about one stop darker than point 9, and reproduces as black. The graph shows where points of these brightness differ ences generally fall on a characteristic curve. Point 9 is exposed on the speed point of the film, which develops to a density of about 0.10 above the base plus fog density (the density of the clear film base after developing). The density range from point 9 to point 2 is about 1.05.
.OG EXPOSURE ( m c s )
21
Representative characteristic curves are those that are typical of a product and are made by averaging the results from a number of tests made on a number of production batches of film. The curves shown in the data sheets are representative curves. Relative characteristic curves are formed by plotting the densities of the test film against the densities of a specific uncalibrated sensitometricstep scale used to produce the test film. These are commonly used in laboratories as process control tools. Blackandwhite films usually have one characteristic curve (see Figures 5 and 6). A color film, on the other hand, has three characteristic curves, one each for the redmodulating (cyancolored) dye layer, the green modulating (magentacolored) dye layer, and the bluemodulating (yellow colored) dye layer (see Figures 7 and 8). Because reversal films yield a positive image after processing, their characteristic curves are inverse to those of negative films (compare Figures 5 and 6).
TYPICAL CHARACTERISTIC CURVES BLACKANDWHITE REVERSAL FILM BLACKANDWHITE NEGATIVE FILM
LOG EXPOSURE (lux/sec)
Figure 5
22
Figure 6
TYPICAL CHARACTERISTIC CURVES COLOR REVERSAL FILM
COLOR N EGATIVE F ILM
LOG EXPOSURE (lux/sec)
Figure 7
LOG EXPOSURE (lux/sec)
Figure 8
General Curve Regions Regardless of film type, all characteristic curves are composed of five regions: Dmin, the toe, the straightline portion, the shoulder and Dmax. Exposures less than at A on negative film or greater than at A on reversal film will not be recorded as changes in density. This constant density area of a blackandwhite film curve is called base plus fog. In a color film, it is termed minimum density or Dmin. The toe (A to B), as shown in Figure 9, is the portion of the characteristic curve where the slope (or gradient) increases gradually with constant changes in exposure (log H). The straightline (B to C), Figure 10, is the portion of the curve where the slope does not change; the density change for a given logexposure change remains constant or linear. For optimum results, all significant picture information is placed on the straightline portion. The shoulder (C to D), Figure 11, is the portion of the curve where the slope decreases. Further changes in exposure (log H) will produce no increase in density because the maximum density (Dmax) of the film has been reached. Base density is the density of fixedout (all silver removed) negative positive film that is unexposed and undeveloped. Net densities produced by exposure and development are measured from the base density. For reversal films, the analogous term of Dmin describes the area receiving total exposure and complete processing. The resulting density is that of the film base with any residual dyes. Fog refers to the net density produced during development of negative positive films in areas that have had no exposure. Fog caused by development may be increased with extended development time or increased developer temperatures. The type of developing agent and the pH value of the developer can also affect the degree of fog. The net fog value for a given development time is obtained by subtracting the base density from the density of the unexposed but processed film. When such values are 23
determined for a scries of development times, a timefog curve (Figure 12) showing the rate of fog growth with development can be plotted.
LOG EXPOSURE (luxsecj
LOG EXPOSURE (luxsec)
Figure 10
Figure 9
LOG EXPOSURE (Iuxsec)
Figure 11
Curve Values You can derive additional values from the characteristic curve that not only illustrate properties of the film but also aid in predicting results and solving problems that may occur during picturetaking or during the developing and printing processes. Speed describes the inherent sensitivity of an emulsion to light under specified conditions of exposure and development. The speed of a film is represented by a number derived from the film's characteristic curve. Contrast refers to the separation of lightness and darkness (called "tones") in a film or print and is broadly represented by the slope of the characteristic curve. Adjectives such as flat or soft and contrasty or hard are often used to describe contrast. In general, the steeper the slope of the characteristic curve, the higher the contrast. The terms gamma and average gradient refer to numerical means for indicating the contrast of the photographic image. Gamma is the slope of the straightline portion of the characteristic curve or the tangent of the angle (a) formed by the straight line with the horizontal. In Figure 5, the tangent of the angle (a) is obtained by dividing the density increase by the log exposure change. The resulting numerical value is referred to as gamma. 24
Gamma does not describe contrast characteristics of the toe or the shoulder. Camera negative films record some parts of scenes, such as shadow areas, on the top portion of the characteristic curve. Gamma does not account for this aspect of contrast. Average gradient is the slope of the line connecting two points bordering a specified logexposure interval on the characteristic curve. The location of the two points includes portions of the curve beyond the straightline portion. Thus, the average gradient can describe contrast characteristics in areas of the scene not rendered on the straightline portion of the curve. Measurement of an average gradient extending beyond the straightline portion is shown in Figure 13. CURVES FOR A DEVELOPMENT TIME SERIES ON A TYPICAL BLACK AND WHITE NEGATIVE FILM
AVERAGE GRADIENT DETERMINATION
LOG EXPOSURE (luxsec)
Figure 12
Figure 13
The particular gamma or average gradient value to which a specific blackandwhite film is developed differs according to the properties and uses of the film. Suggested control gamma values are given on the data sheets for blackandwhite negative and positive films. If characteristic curves for a blackandwhite negative or positive film are determined for a series of development times and the gamma or average gradient of each curve is plotted against the time of development, a curve showing the change of gamma or average gradient with increase development is obtained. You can use the timegamma curve (Figure 14) to find the optimum developing time to produce the control gamma values recommended in the data sheet (or any other gamma desired). Blackandwhite reversal and all color film processes are not controlled by using gamma values.
25
Flashing camera films to lower contrast is a technique* that involves uniformly exposing film before processing to lower its overall contrast. It's used with some color films. It is actually an intentional light fogging of the film. You can make the flashing exposure before or after the subject exposure, either in a camera or in a printer. The required amount of exposure and the color of the exposing light depends on the effect desired, the point at which the flashing exposure is applied, the subject of the main exposure, and the film processing. Because of potential latent image changes, a flashing exposure just prior to processing is the preferred method.
DEVELOPMENT TIME (IN MINUTES)
Figure 14
2.00
I 00
LOG EXPOSURE (luxsec)
Figure 15
* "Flashing of EASTMAN EKTACHROME Video News Films for Intercutting with EASTMAN EKTACHROME Commercial Film 7252" by Doody, Lawton, and Perry, Journal of the SMPTE June, 1978, Vol. 78.
26
This fairly common practice is often used to create a closer match of two films' contrast characteristics when they are intercut. The hypothetical characteristic curves in Figure 15 show what occurs when one film is flashed to approximately match another film's characteristic curve. The illustration has been simplified to show an ideal matching of the two films. In practice, results will depend on the tests run using the specific films intended for a production. Some film productions use flashing (called "creative flashing") to alter the contrast of the original camera negative of a particular scene to create a specific effectmaking pastels from more saturated colors, enhancing shadow detail, and the like. Further discussion of this type of flashing is presented in "Creative PostFlashing Technique for the The Long Goodbye," American Cinematographer Magazine, March 1973. Color Sensitivity and Spectral Sensitivity The term color sensitivity is used on data sheets for some blackandwhite films to describe the portion of the visual spectrum to which the film is sensitive. All blackandwhite camera films are panchromatic (sensitive to the entire visible spectrum). Some laboratory films are also panchromatic: EASTMAN Fine Grain Duplicating Panchromatic Negative Film, EASTMAN Panchromatic Separation Film, and EASTMAN High Contrast Panchromatic Film. Some films, called orthochromatic, are sensitive mainly to the blueand green portions of the visible spectrum. EASTMAN Direct MP, EASTMAN Reversal BW Print, and EASTMAN Sound Recording II Films are all orthochromatic laboratory or print films. Films used exclusively to receive images from blackandwhite materials are bluesensitive: EASTMAN Fine Grain Release Positive Film, EASTMAN High Contrast Positive Film, and EASTMAN Fine Grain Duplicating Positive Film. One film is sensitive to blue light and ultraviolet radiation: EASTMAN Television Recording Film. The extended sensitivity in the ultraviolet region of the spectrum permits the film to respond to the output of cathode ray tubes. While color films and panchromatic blackandwhite films are sensitive to all wavelengths of visible light, rarely are two films equally sensitive to all wavelengths. Spectral sensitivity describes the relative sensitivity of the emulsion to the spectrum within the film's sensitivity range. The photographic emulsion has inherently the sensitivity of photosensitive silver halide crystals. These crystals are sensitive to highenergy radiation, such as Xrays, gamma rays, ultraviolet radiation and b luelight wavelengths (blue sensitive blackandwhite films). In conventional photographic emulsions, sensitivity is limited at the short (ultraviolet) wavelength end to about 250 nanometers (nm) because the gelatin used in the photographic emulsion absorbs much ultraviolet radiation. The sensitivity of an emulsion to the longer wavelengths can be extended by the addition of suitably chosen dyes. By this means, the emulsion can be made sensitive through the green region (orthochromatic blackandwhite films), through the green and red regions (color and panchromatic blackandwhite films), and into the near 27
infrared region of the spectrum (infraredsensitive film). See Figure 16. Three spectral sensitivity curves are shown for color f i l m s o n e each for the redsensitive (cyandye forming), the greensensitive (magentadye forming), and the bluesensitive (yellowdye forming) emulsion layers. One curve is shown for blackandwhite films. The data are derived by exposing the film to calibrated bands of radiation 10 nanometers wide throughout the spectrum, and the sensitivity is expressed as the reciprocal of the exposure (ergs/cm2) required to produce a specified density. The radiation expressed in nanometers is plotted on the horizontal axis, and the logarithm of sensitivity is plotted on the vertical axis to produce a spectralsensitivity curve, as shown in Figure 17.
Normal Photographic Section of the Electromagnetic Spectrum 100 nanometers 1000 nanometers 10.000 nanometers
ULTRAVIOLET RADIATION
INFRARED RADIATION
VISIBLE SPECTRUM Blue
Green
Panchromatic
Orthochromatic
Figure 16
Blue Sensitive
Film sensitivities
28
Rec
Equivalent neutral density ( E N D ) W h e n the amounts of the components of an image are expressed in this unit, each of the density figures tells how dense a gray that component can form. Because each emulsion layer of a color film has its own speed and contrast characteristics, equivalent neutral density (END) is derived as a standard basis for comparison of densities represented by the spectral sensitivity curve. For color films, the standard density used to specify spectral sensitivity is as follows: For reversal films, END = 1.0 For negative films, direct duplicating, and print films, END = 1.0 above Dmin. SpectralDyeDensity Curves Processing exposed color film produces cyan, magenta, and yellow dye images in the three separate layers of the film. The spectraldyedensity curves (illustrated in Figure 18) indicate the total absorption by each color dye measured at a particular wavelength of light and the visual neutral density (at 1.0) of the combined layers measured at the same wavelengths. Spectraldyedensity curves for reversal and print films represent dyes normalized to form a visual neutral density of 1.0 for a specified viewing and measuring illuminant. Films which are generally viewed by projection are measured with light having a color temperature of 5400 K. Colormasked films have a curve that represents typical dye densities for a midscale neutral subject. The wavelengths of light, expressed in nanometers (nm), are plotted on the horizontal axis, and the corresponding diffuse spectral densities are plotted on the vertical axis. Ideally, a color dye should absorb only in its own region of the spectrum. All color dyes in use absorb some wavelengths in other regions of the spectrum. This unwanted absorption, which could prevent satisfactory color reproduction when the dyes are printed, is corrected in the film's manufacture. In color negative films, some of the dyeforming couplers incorporated in the emulsion layers at the time of manufacture are colored and are evident in the Dmin of the film after development. These residual couplers provide automatic masking to compensate for the effects of unwanted dye absorption when the negative is printed. This explains why negative color films look orange. Since color reversal films and print films are usually designed for direct projection, the dyeforming couplers must be colorless. In this case, the couplers are selected to produce dyes that will, as closely as possible, absorb in only their respective regions in the spectrum. If these films are printed, they require no printing mask.
29
Process: ECN2 Density. 1.0 above Dmin Densitometry: Status M
Yelowforming Layer Magenta forming Layer
400
500
600
700
WAVELENGTH (nm)
Figure 17
Normalized dyes to form a visual neutral density of 1.0 for a viewing illuminant of 3200 K.
400
450
500
550
WAVELENGTH (nm)
Figure 18
30
600
650
700
Image Structure The sharpness of image detail that a particular film type can produce cannot be measured by a single test or expressed by one number. For example, resolvingpowertest data gives a reasonably good indication of image quality. However, because these values describe the maximum resolving power a photographic system or component is capable of, they do not indicate the capacity of the system (or component) to reproduce detail at other levels. For more complete analyses of detail quality, other evaluating methods, such as the modulationtransfer function and film granularity, are often used. An examination of the modulationtransfer curve, RMS granularity, and both the high and lowcontrast resolving power listings will provide a good basis for comparison of the detailimaging qualities of different films. ModulationTransfer Curve Modulation transfer relates to the ability of a film to reproduce images of different sizes. The modulationtransfer curve describes a film's capacity to reproduce the complex spatial frequencies of detail in an object In physical terms, the measurements evaluate the effect on the image of light diffusion within the emulsion. First, film is exposed under carefully controlled conditions to a series of special test patterns, similar to that illustrated in (a) of Figure 19. After development, the image (b) is scanned in a microdensitometer to produce trace (c).
Figure 19 Image (b) of * sinusoidal lest object (a) recorded on a photographic emulsion and a micro densitometer tracing (c) of the image.
31
The resulting measurements show the degree of loss in image contrast at increasingly higher frequencies as the detail becomes finer. These losses in contrast are compared mathematically with the contrast of the portion of the image unaffected by detail size. The rate of change or "modulation" (M) of each pattern can be expressed by this formula in which E represents exposure: M = E maxE min E max+E min When the microdensitometer scans the test film, the densities of the trace are interpreted in terms of exposure, and the effective modulation of the image (Mi) is calculated. The modulationtransfer factor is the ratio of the modulation of the developed image to the modulation of the exposing pattern (Mo), or Mi/Mo. This ratio is plotted on the vertical axis (logarithmic scale) as a percentage of response. The spatial frequency of the patterns is plotted on the horizontal axis as cycles per millimeter. Figure 20 shows two such curves. At lower magnifications, the test film represented by curve A appears sharper than that represented by curve B; at very high magnifications, the test film represented by curve B appears sharper.
SPATIAL FREQUENCY (cycles/mm)
Figure 20
All of the photographic modulationtransfer curves in the data sheets were determined using a method similar to that specified by ANSI Standard PH2.391977. The films were exposed with the specified illuminant to spatially varying sinusoidal test patterns having an aerialimage modulation of a nominal 35 percent at the image plane, with processing as indicated. In practice, most photographic modulationtransfer values are influenced by development adjacency effects and are not exactly equivalent to the true optical modulationtransfer curve of a particular photographic product. Modulationtransfer measurements can also be made for the nonfilm components in a photographic system such as cameras, lenses, printers, etc, to analyze or predict the sharpness of the entire system. By multiplying the responses for each ordinate of the individual curves, you can combine the modulationtransfer curve for a film with similar curves for an optical system to calculate the modulationtransfer characteristics of the entire system. 32
Graininess and G ranularity The terms graininess and granularity are often confused or even used as synonyms in discussions of silver or dyedeposit distributions in photographic emulsions. The two terms refer to two distinctly different ways of evaluating the image structure. When a photographic image is viewed with sufficient magnification, the viewer experiences the visual sensation of graininess, a subjective impression of nonuniformity in an image. This nonuniformity in the image structure can also be measured objectively with a microdensitometer. This objective evaluation measures film granularity. Motion picture films consist of silver halide crystals dispersed in gelatin (the emulsion) which is coated in thin layers on a support (the film base). The exposure and development of these crystals forms the photographic image, which is, at some stage, made up of discrete particles of silver. In color processes, where the silver is removed after development, the dyes form dye clouds centered on the sites of the developed silver crystals. The crystals vary in size, shape, and sensitivity, and generally are randomly distributed within the emulsion. Within an area of uniform exposure, some of the crystals will be made developable by exposure; others will not The location of these crystals is also random. Development usually does not change the position of a grain, so the image of a uniformly exposed area is the result of a random distribution either of opaque silver particles (black andwhite film) or dye clouds (color film), separated by transparent gelatin (Figures 21 and 22).
Figure 21 Grains of silver halide are randomly dis tributed in the emulsion when it is made. This photomicrograph of a raw emulsion shows silver halide crystals.
Figure 22 Silver is developed or clouds of dye formed at the sites occupied by the exposed silver halide. Contrary to widely held opinion, there is little migration or physical joining of individual grains. Compare the distribution of silver parti cles in this photomicrograph with the undeveloped silver halide in Figure 21
33
Although the viewer sees a granular pattern, the eye is not necessarily seeing the individual silver particles, which range from about 0.002 mm down to about a tenth of that size. At magnifications where the eye cannot distinguish individual particles, it resolves random groupings of these particles into denser and less dense areas. As magnification decreases, the observer progressively associates larger groups of spots as new units of graininess. The size of these compounded groups gets larger as the magnification decreases, but the amplitude (the difference in density between the darker and the lighter areas) decreases. At still lower magnifications, the graininess disappears altogether because no granular structure can be seen (Figure 23).
Figure 23
34
(a) A 2.5X enlargement of a negative shows no apparent graininess. (b) At 20X, some graininess shows, (c) When a segment of the negative is inspected at 60X, the indi vidual silver grains start to become distin guishable, (d) With 400X magnification, the discrete grains are easily seen. Note that surface grains are in focus while grains deeper in the emulsion are out of focus. The apparent "clumping" of silver grains is actually caused by overlap of grains at different depths when viewed in twodimensional projection, (e) The make up of individual grains takes different forms. This filamentary silver, enlarged by an electron microscope, appears as a single opaque grain at low magnification.
Randomness is a necessary condition for the phenomenon. If the particles were arranged in a regular pattern like the halftone dot pattern used in graphic arts, no sensation of graininess would be created. When a halftone is viewed at a magnification sufficient for the dots to be distinguished, the eye notices the pattern and does not group dots into new patterns. Even though the dot pattern can be seen, the eye does not perceive graininess because the pattern is regular, not random (Figure 24). At lower magnificationsat which the dots can no longer be resolvedthe awareness of pattern ceases, and the image areas appear uniform.
Figure 24 If the uniform dot pattern of a conventional halftone is used to reproduce a scene, the eye accepts the image as a smooth, continuoustone rendition (a). This hap pens because the dotsare regularly spaced. However, when the halftone dots are dis
tributed randomly in an area to reproduce a scene (b) the image looks "grainy." Graininess in the image is due, in part, to the random distribution of the individual elements which make up that image.
When you view a random pattern of small dots magnified enough to resolve the individual dots, you do not perceive an orderly or intelligible pattern. When the magnification is decreased so the dots cannot be resolved, they appear to blend together to form an image whose surface is nonuniform or grainy. Measuring RMS Granularity The attributes of the photographic image which cause the human eye to perceive graininess can also be measured (and simulated) by an electro optical system in a microdensitometer. These measurements are analyzed statistically to provide numerical values that correlate with the visual impression of graininess. The two major advantages of objective measurement are that instruments can be devised to make rapid and precise measurements and that these measurements can be manipulated readily by mathematical means. 35
Ordinary densitometers measure density over areas much larger than those of individual silver particles. Since there are so many particles in the aperture of an ordinary densitometer, small variations in the number of particles measured will not affect the reading. Just as higher magnification increases the apparent graininess, a decrease in the aperture produces higher granularity values. When the aperture of the densitometer is considerably reduced, fewer particles are included and a small change in their number is recorded as a variation in density. Analysis of the magnitude of these variations gives a statistical measure of the granularity of a sample. In practice, an area of apparently uniform density is continuously scanned by the small aperture usually 48 nanometers in diameter (see Figure 25). The transmitted light registers on a photosensitive pickup, and the current produced is then fed to a meter calibrated to read the standard deviation of the randomdensity fluctuations (see Figure 26).
Figure 25 A large aperture "sees" a vast number of individual silver grains. Therefore, small local fluctuations have practically no effect on the density it records. Small apertures (about one twentieth of the larger aperture diameter) detect random differences in grain distribution when they sample the large "uniform" area.
36
Figure 26 The signal from a continuous density scan of a grainy emulsion appears the same as random electrical noise when displayed on an oscilloscope. The rms voltmeter gives a direct readout of "noise level."
Standard deviation describes the distribution of a group of values (in this case, variations in density) about their average. The square root (R) of the arithmetic mean (M) of the squares (S) of the density variations is calculatedhence, the term RMS granularity. For ease of comparison, this small decimal number is multiplied by a factor of 1,000, yielding a small whole number, typically between 5 and 50. The RMS granularity instrument used at Kodak is calibrated to measure American National Standard (PH2.191976) diffuse visual density. The granularity values for Kodak blackandwhite and color negative films are determined at a net visual density of 1.00. KODAK and EASTMAN Motion Picture Films are read with a circular aperture 48 micrometers (0.048 mm) in diameter. This aperture gives meaningful readings over the widest range of film samples. Factors That Affect Graininess Different developers and different amounts of development affect the graininess of blackandwhite films. The amount of exposure, which determines the densities of various areas, also affects the graininess of all films. Because the development processes of color films are rigidly fixed, the effect of development is rarely a factor in their graininess, although force processing does cause an increase. Because many color films are made with emulsion layers of varying graininess levels, increasing the exposure (up to a point) places more of the density in the finer grained layers, which actually reduces the overall graininess of the observed images. Granularity and Color Materials One might expect a photographic image made up of cyan, magenta, and yellow dye clouds to appear more grainy than the corresponding silver image because of color contrast. In fact, close to its resolution limit, the eyes sees only brightness differences and does not distinguish color in very small detail. When color films are projected, the dyecloud clusters form groups similar to silvergrain clusters in blackandwhite films. At high magnifications, these clusters cause the appearance of graininess in the projected screen image. Some Practical Effects of Graininess and Granularity With the trend to smaller camerafilm formats, has come the need for greater enlargement of the projected image. At the same time, viewers are increasingly aware of the granular structure of films. The photographer wants a finegrain film but not at the expense of sensitivity or film speed. Faster films usually have larger grains because larger silver halide crystals have a greater probability of being struck by light and made developable. Large silver halide crystals normally develop to larger particles of metallic silver. Thus, the selection of a film is usually a compromise between available speed and tolerable grain. Photographic scientists are constantly seeking more favorable speed grain ratios, but the relationship of emulsion speed to the grain structure is also a vital concern to the photographer because the speedgrain relationship indicates whether the emulsion will detect light and, if detected, will form a 37
recognizable image. If a biologist needs to film the life processes of an amoeba, the amount of allowable light is partly limited by the temperature tolerance of the amoeba. If fast film is used to compensate for limited light, the granularity must be low enough for the film to record the detail required by the application. Certainly the viewer should not have to wonder whether the movement on the screen is the amoeba's digestive process or "crawling" grain clusters. Graininess is most evident in the midtones of a print (i.e., densities of about 0.6 to 0.9). The light tones of the print are on the toe of the characteristic curve where the slope is very much lower than unity. Hence, the contrast with which the graininess is reproduced is very lowdecreasing its visibility. In dark tones, the eye is less able to distinguish graininess. The eye easily detects density differences as low as 0.02 in the average highlight density, but can detect density differences only on the order of 0.20 in the average shadow density. In the midtones, where the slope of the curve is constant, the print material has its maximum contrast and the eye can more readily distinguish small density differences; therefore, the granularity can be most easily detected by the eye as graininess. Another factor in perceiving graininess is the amount of detail in a scene. Graininess is most apparent in large areas with fairly uniform densities and is much less evident in areas full of fine detail or motion. It is difficult to predict the magnification at which projected print images will be viewed since both the projection magnification and the distance from the observer to the screen can very. Both factors affect the picture magnification, and thus the graininess. When a motion picture film is seen at great magnification (as from a frontrow theater seat), the viewer may be aware of grains "boiling" or "crawling" in uniform areas of the image. This sensation is caused by the frametoframe changes of grain positions, which make graininess more noticeable in a motion picture than in a still photograph. Conversely, the moving image tends to distract the viewer's attention away from this sensation, and graininess is, therefore, usually noticed only in static scenes.
Resolving Power The resolving power of a film emulsion refers to its ability to record fine detail. It is measured by photographing resolution charts or targets under exacting test conditions. The parallel lines on resolution charts are separated from each other by spaces the same width as the lines. The chart contains a series of graduated parallelline groups, each group differing from the next smaller or next larger by a constant factor. The targets are photographed at a great reduction in size, and the processed image is viewed through a microscope. The resolution is measured by a visual estimate of the number of lines per millimeter that can be recognized as separate lines. The measured resolving power depends on the exposure, the contrast of the test target, and, to a lesser extent, the development of the film. The resolving power of a film is greatest at an intermediate exposure value, falling off greatly at high and lowexposure values. Obviously, the loss in resolution that accompanies under or overexposure is an important reason for observing the constraints of a particular film when making exposures. 38
Resolution also depends on the contrast of the image, hence, the contrast of the target. Test exposures are usually made with both a highcontrast (luminance ratio 1000:1) and a lowcontrast (1.6:1) target. A film resolves finer detail when the image contrast is higher. Both high and lowcontrast resolvingpower values are determined according to a method similar to the one described in ANSI No. PH2.331969 IR1976). "Method for Determining the Resolving Power of Photographic Materials," are given on the data sheets. The resolving power reported is based on film exposed and processed as recommended. The maximum resolution obtainable in practical photographic work is limited both by the camera lens and by the film. The formula often used to predict the resolution of a camera original is 1 = RS2
1 RF2
+
1 RL2
RS = Resolution of the system (lens + film) RF = Resolution of the film RL = Resolution of the lens In practice, other external factors, such as camera movement, focus, aerial haze, etc, also decrease the resolution from the possible maximum.
39
PHYSICAL CHARACTERISTICS Film Base The film base is the plastic support that carries the lightsensitive emulsion. Requirements for a suitable film base include optical transparency, freedom from optical imperfections, chemical stability, photographic inertness, and resistance to moisture and processing chemicals. Mechanical strength, resistance to tearing, flexibility, dimensional stability, and freedom from physical distortion are also important factors in processing, printing, and projection. Two general types of film base are currently usedcellulose triacetate esters and a synthetic polyester polymer known as ESTAR Base. Cellulose triacetate film base is made by combining the cellulose triacetate with suitable solvents and a plasticizer. Most current KODAK and EASTMAN Motion Picture Films are coated on a cellulose triacetate base. ESTAR Base, a polyethylene terephthalate polyester, is used for some KODAK and EASTMAN Motion Picture Films (mostly intermediate and print films) because of its high strength, chemical stability, toughness, tear resistance, flexibility, and dimensional stability. The greater strength of ESTAR Base permits the manufacture of thinner films that require less room for storage. ESTAR Base films and other polyester base films, cannot be successfully spliced with readily available commercial film cements. You can splice these films with a tape splicer or with a splicer that uses an ultrasonic or an inductive heating current to melt and fuse the film ends.
Antihalation Backing Light penetrating the emulsion of a film can be reflected from the base emulsion interface back into the emulsion. As a result, there is a secondary exposure causing an undesirable reduction in the sharpness of the image and some light scattering, called halation, around images of bright objects. See Figure 27. A dark layer coated on or in the film base will absorb and minimize this reflection, hence it is called an antihalation layer. Three methods of minimizing halation are commonly used: Rem Jet: A blackpigmented, nongelatin layer on the back of the film base serves as an antihalation and antistatic layer. This layer is removed during photographic processing. Antihalation under coating: A silver or dyed gelatin layer directly beneath the emulsion is used on some thin emulsion films. Any color in this layer is removed during processing. This type of layer is particularly effective in preventing halation for highresolution emulsions. An antistatic and/or anticurl layer may be coated on the back of the film base when this type of antihalation layer is used.
Figure 27
Light Piping
40
Dyed film base: Film bases, especially polyester, can also transmit or pipe light that strikes the edge of the film. This light can travel inside the base and fog the emulsion (Figure 27). A neutraldensity dye is incorporated in some film bases and serves to both reduce halation and prevent light piping. This dye density may vary from a just detectable level to approximately 0.2. The higher level is used primarily for halation protection in blackandwhite negative films on cellulosic bases. Unlike fog, the gray dye does not reduce the density range of an image, because it, like a neutral density filter, adds the same density to all areas. It has, therefore, a negligible effect on picture quality.
Edge Numbers Edge numbers (also called key numbers or footage numbers) are placed at regular intervals along the film edge for convenience in frameforframe matching of the camera film to the workptint. The numbers are printed along one edge outside the perforations on 35 mm film and between the perforations on 35 mm film and between the perforations on 16 mm film. The numbers are sequential, usually occurring every 16 frames (every 12 inches) on 35 mm film and every 20 frames (every 6 inches) on 16 mm film. In a few instances, edge numbers on 16 mm films are located every 40 frames (12 inches). All Kodak camera film is edge numbered at the time of manufacture in one of two ways: Latent Image: The film edge is exposed by a printer mounted at the perforator to produce an image visible only on processed film. The five or seven digits are sequential and will change every 16 (35 mm) or 20 (16 mm) frames. The cluster of numbers and letters to the left of the sequential numbers are a manufacturer's code for the type of product, the perforator, and the equipment used to produce the product All Kodak 16 mm and 35 mm camera color film is latentimage edge numbered (Figure 28). Visible Ink Image: During manufacturing, the film stock is numbered with a visible ink. Again, this process is performed at the perforators. The ink, unaffected by photographic chemicals, is printed on the emulsion surface of the film. The numbers are visible on both the raw stock and the processed film. In Figure 29, the visible ink edge numbering will be more visible after processing. All 35 mm Kodak blackandwhite motion picture camera films have ink edge numbers. The letter "C" is a manufacturer's product identification.
Figure 28 Latent image edge numbering
41
A third method of applying edge numbering is very often used by commercial motion picture labs. There the film is numbered on the base side, generally with yellow ink. This numbering does not interfere with the manufacturer's edge numbers because the lab numbers are ordinarily printed on the opposite edge of the film. Normally, both the original camera film and the workprint are edge numbered identically for later ease in matching the two. Figure 30 is a sample of EASTMAN EKTACHROME Video News Film 7240 (Tungsten), edge numbered by a laboratory in New York City. With doublesystem sound, both the film and the magnetic tape are often edge numbered by the lab for ease of editing.
Visible ink edge numbering
Laboratory applied edge numbering
Figure 29
Figure 30
In 1990, Eastman Kodak Company introduced a new edgenumbering system that will eventually be included on all Eastman camera negative films, both blackandwhite and color. The new system incorporates EASTMAN KEYKODETM numbers which are machine readable in bar code. A variety of scanners can read this bar code in the same way that the bar code on most products in supermarkets is read by a scanner in the checkout line. The humanreadable key numbers are similar to previous edge numbers, but are easier to read. In this improved format, the key number consists of 12 highly legible characters printed at the familiar onefoot, 64 perforation interval. The KEYKODETM number incorporates the same humanreadable number, but in a bar code. See Figures 31 and 32.
42
Figure 31
43
Figure 32
44
Dimensional Change Characteristics Motion picture film dimensions are influenced by variations in environmental conditions. The film swells during processing, shrinks during drying, and continues to shrink at a decreasing rate throughout its life. These dimensional changes in film are either temporary (reversible) or permanent (irreversible). Temporary size changes are caused by a modification in the moisture content or the temperature of the film. The extent of both temporary and permanent size alterations is largely dependent upon the film support. However, since the emulsion is considerably more hygroscopic than the base, it also has a marked influence on dimensional variations caused by humidity. Permanent shrinkage of film on cellulose triacetate support is due to loss of residual solvents or plasticizer, and, to a slight extent, the gradual elimination of strains introduced during manufacture or processing. ESTAR Base has no residual solvent or plasticizer and absorbs less moisture than cellulose triacetate; consequently, its size changes are considerably less. Some permanent shrinkage occurs in aging of raw stock processing, and aging of processed film. Values for the dimensions change characteristics of current KODAK and EASTMAN Motion Picture Films are given in the table below.
Approximate Dimensional Change Characteristics of Current KODAK and EASTMAN Motion Picture Films
(a) Measured between 15% and 50% RH at 211C (70° F) (b) Measured between 49°C (12°F ) and 21°C (70°F ) at 20% RH (c) Tray processing measured at 21 °C (70° F) and 50% RH after preconditioning at low relative humidity (d) Over a period of years at normal conditions, and shorter times at elevated temperatures or humidities
Temporary Size Change Moisture. Relative Humidity (RH) of the air is the major factor affecting the moisture content of the film, thus governing the temporary expansion or contraction of the film (assuming constant temperature). For camera films, the humidity coefficients are slightly higher than for positive print films. The coefficients given in the table above are averages for the range of 15 to 50percent RH, where the relationship between film size and relative 45
humidity is approximately linear. For ESTAR Base films, this coefficient is larger at lower humidity ranges, and smaller at higher humidity ranges. When a given relative humidity level is approached from above, the exact dimensions of a piece of film on cellulose triacetate support may be slightly larger than when the level is approached from below. The opposite is true for ESTAR Base films, which will be slightly larger when the film is previously conditioned to a lower humidity than it would be if conditioned to a higher humidity. Temperature. Photographic film expands with heat and contracts with cold in direct relationship to the film's thermal coefficient The thermal coefficients for current KODAK and EASTMAN Motion Picture Films are listed in the table on page 45. Rates of Temporary Change. Following a shift in the relative humidity of the air surrounding a single strand of film, humidity size alterations occur rapidly in the first 10 minutes and continue for about an hour. If the film is in a roll, this time will be extended to several weeks because the moisture must follow a longer path. In the case of temperature variations, a single strand of film coming in contact with a hot metal surface, for example, will change almost instantly. A roll of film, on the other hand, requires several hours to alter size. Swell during Processing. All motion picture films swell during photographic processing and shrink during drying. The swell of triacetate films is initially rapid and depends upon the temperature of the processing solutions, time, and film tension. Acetate films swell more in the widthwise than in the lengthwise direction, and negative films swell more than print films. The change for ESTAR Base films is much smaller. The effects of drying upon the final dimensions are discussed in the section on permanent size change. Swell % Base
Film Type
Width
Negative
Triacetate
0.4
0.6
Positive— BlackandWhite and Color
Triacetate
0.3
0.5
Reversal Color
AcetatePropionate
0.6
0.8
Positive Color
ESTAR
0.05
0.05
SWELL DURING PROCESSING
MINUTES AT 21°C (70°F ) IN PROCESSING SOLUTIONS
46
Length
Permanent Size Change Permanent size change is the summation of the shrinkage of the raw film, the size change due to processing, and the shrinkage of the processed film. Raw Stock Shrinkage. Immediately after slitting and processing, the unexposed motionpicture film is placed in cans that are sealed with tape. Until the film is removed from the can, solvent loss from triacetate film is extremely low. The lengthwise shrinkage will rarely exceed 0.5 percent during the first 6 months in a 1000foot can of 35 mm film. ESTAR Base films will not shrink more than 0.2 percent while in a taped can. Processing Shrinkage. The net effect of processing triacetate base film is normally slight shrinkage (see the table on page 45) unless the film has been stretched. Some commercial processing machines have sufficiently high tension to stretch the wet film (particularly 16 mm film); consequently, a lower net processing shrinkage or even a slight permanent stretch may result. Because of its greater strength and resistance to moisture, the overall size change of ESTAR Base films is much less. Aging shrinkage. It is important that motion picture negatives, internegatives, and color originals have low aging shrinkage so that you can make satisfactory prints or duplicates even after many years of storage. With motion picture positive film intended for projection only, shrinkage is not especially critical because it has little effect on projection. The rate at which aging shrinkage occurs depends upon the conditions of storage and use. Shrinkage is hastened by high temperature and, in the case of triacetate films, by high relative humidity which aids the diffusion of solvents from the film base. The potential aging shrinkage of current motionpicture films is given in the table on page 45. In the case of processed negatives made on stock manufactured since June 1954, the potential lengthwise shrinkage of about 0.2 percent is generally reached within the first two years and almost no further shrinkage occurs thereafter. This very small net change is a considerable improvement over the shrinkage characteristics of negative materials available before 1954 and permits good printing even after long periods of keeping. The lengthwise shrinkage of release prints made on triacetate supports is about 0.1 to 0.3 percent for 35 mm film and 0.1 to 0.4 percent for 16 mm film during the first two years. Higher shrinkage can occur over a longer period, as indicated in the table on page 45. Shrinkage of films on ESTAR Base is unlikely to exceed 0.04 percent. Although aging shrinking of motion picture films is a permanent size change, humidity and thermal size changes can either increase or decrease the observed size change.
47
Other Physical Characteristics Aside from image quality considerations, other factors can affect the satisfactory performance of motion picture film. Curl Photographicfilm curl is defined as the departure from flatness of photographic film. Curl toward the emulsion is called positive while curl away from the emulsion is termed negative. Although the curl level is established during manufacture, it is influenced by the relative humidity during use or storage, processing and drying temperatures, and the winding configuration.
Figure 33
At low relative humidities, the emulsion layer contracts more than the base generally producing positive curl. As the relative humidity increases, the contractive force of the emulsion layer decreases and the inherent curl of the support becomes dominant. Film wound in rolls tends to assume the lengthwise curl conforming to the curve of the roll. When a strip of this curled film is pulled into a flat configuration, the lengthwise curl is transformed into a widthwise curl. Buckling and Fluting Very high or low relative humidity can also cause abnormal distortions of film in rolls. Buckling, caused by the differential shrinkage of the outside edges of the film, occurs if a tightly wound roll of film is kept in a very dry atmosphere. Fluting, the opposite effect, is caused by the differential swelling of the outside edges of the film; it occurs if the roll of film is kept in a very moist atmosphere. To avoid these changes, do not expose the film rolls to extreme fluctuations in relative humidity.
48
Additional reading on "Physical Characteristics of Film." Adelstein, P. Z. and Calhoun, J. M., "Interpretation of Dimensional Changes in Cellulose Ester Base Motion Picture Films," Journal of the SMPTE, 69:15763, March 1960. Adelstein, P. Z. Graham, C. L., and West, L. E., "Preservation of Motion Picture Color Films Having Permanent Value," Journal of the SMPTE, 79:10111018, November 1970. Calhoun, J. M., "The Physical Properties and Dimensional Behavior of Motion Picture Films," Journal of the SMPTE, 43:22766, October 1944. Fordyce, C. R., "Improved Safety Motion Picture Film Support," Journal of the SMPTE, 51:33150, October 1948. Fordyce, C. R., Calhoun, J. M., and Moyer, E. E., "Shrinkage Behavior of Motion Picture Film," Journal of the SMPTE, 64:6266, February 1955. Miller, A. J. and Robertson, A. C., "Motion Picture FilmIts Size and Dimensional Characteristics," Journal of the SMPTE, 74:311, January 1965. Neblette, C. E.,"PhotographyIts Materials and Process," Chapter 11, D. VanNostrand Co., Inc., 1962
49
STORAGE OF RAW AND EXPOSED FILM The sensitometric characteristics of virtually all unprocessed photographic materials gradually change with time, causing loss in sensitivity, a change in contrast, a growth in fog level, or possibly all three. In color films, the rates at which the various colorsensitive layers respond are not necessarily the same, thus the color balance of the material can also change. Improper storage usually causes much larger changes in color quality and film speed than do variations in manufacturing. Scrupulous control of temperature and humidity, thorough protection from harmful radiation and gases, and careful handling are important to long, useful film life. This section explains how to store raw film stock and exposed but unprocessed film. The chart on page 51 summarizes optimum storage conditions.
Raw Stock in Original Package Temperature In general, the lower the temperature at which a film is stored, the slower will be its rate of sensitometric change during aging. For periods up to six months, motion picture raw stock should be stored at a temperature of 13°C (55°F) or lower during the entire storage period if optimum film properties are to be retained. Raw stock should be stored at 18° to 23°C (0° to 10°F) if it must be kept longer than six months or if the film is intended for a critical use that requires uniform results. Sensitometric change cannot be prevented by such storage, but it will be minimized. IMPORTANT: After removing a package of raw stock from cold storage, allow it to warm up to room temperature (70°F ±5°F) before opening the can. This will prevent telescoping of the roll during handling because of coldinduced looseness between the layers and will prevent moisture condensation and spotting of the film.
Radiation Do not store or ship raw stock near Xray sources or other radioactive materials. Some scanning devices used by postal authorities and airlines may fog raw stock. Take special storage precautions in hospitals, industrial plants, and laboratories where radioactive materials are in use. Label packages of unprocessed films that must be mailed across international borders: "Contents: Unprocessed photographic film. Please do not Xray." 50
*After removal from storage, keep sealed (in original cans) until temperature is above the dew point of outside air. (See table of warm up times.) Exposed film should be processed as soon as possible after exposure.
t
Gases and Vapors Gases (such as formaldehyde, hydrogen sulfide, sulfur dioxide, ammonia, illuminating gas, engine exhaust) and vapors (from solvents, mothballs, cleaners, turpentine, mildew and fungus preventives, and mercury) can change the sensitivity of photographic emulsions. The cans in which motion picture film is packaged provide protection against some gases, but others can slowly penetrate the adhesive tape seal. Keep film away from any such contaminationfor example, closets or drawers that contain mothballsotherwise, desensitization of the silver halide grains or chemical fogging can occur. Relative Humidity Since a small amount of vapor leakage through the closure of a taped can is unavoidable, give motion picture films additional watervapor protection if they are to be kept longer than a month in an area having high relative humidity (70 percent or higher), such as home refrigerators or damp basements. Protect unopened rolls by tightly sealing them in a second plastic container or can. NOTE: It is the relative humidity, not the absolute humidity, that determines the moisture content of film. Relative humidity is best measured with a sling psychrometer. In a small storage chamber, a humidity indicator, such as those sold for home use, is satisfactory. Handling Storage rooms for motionpicture raw stock should be designed so that accidental flooding from storms, water pipes, or sewers cannot damage the product. Store all film at least 15 cm (6 in.) off the floor. Construct and insulate rooms that are artificially cooled so that moisture does not condense on the walls. If the building itself is not fireproof, install sprinklers. As indicated, control of relative humidity below 70 percent is not critical as long as the film cans remain sealed. Maintain the temperature as 51
uniform as possible throughout the storage room by means of adequate air circulation so that sensitometric properties remain consistent, roll to roll. Do not store film near heating pipes or in the line of sunlight coming through a window, regardless of whether the room is cool or not.
Unprocessed Film before and after Exposure General Concerns Once you open the original package, the film is no longer protected from high relative humidities that can cause undesirable changes. Exposed footage is even more vulnerable to the effects of humidity and temperature. Therefore, process film as soon as possible after exposure. Temperature Protect film in original packages or loaded in cameras, cartridges, magazines, on reels, and in carrying cases from direct sunlight and never leave film in closed spaces that may trap heat. The temperatures in closed automobiles, parked airplanes, or the holds of ships, for example, can easily reach 60°C (140°F) or more. A few hours under these conditions, either before or after exposure, can severely affect the quality of the film. If processing facilities are not immediately available, store exposed films at 18°C(0°F). Gases and Radiation Keep films away from the harmful gases and radiation mentioned earlier. Relative Humidity When handling motionpicture film in high relative humidities, it is much easier to prevent excessive moisture takeup than it is to remove it. If there are delays of a day or more in shooting, remove the magazine containing partially used film from the camera and place it in a moisturetight dry chamber. This prevents any absorption of moisture by the film during the holding period. Immediately after exposure, return the film to its can and retape it to prevent any increase in moisture content over that picked up during actual exposure. Moisture leakage into a taped can is more serious when the can contains only a small quantity of film. When these circumstances exist, seal as many rolls as possible in a second moisture resistant container. Handling Handle the film strand only by the edges to avoid localized changes in film sensitivity caused by fingerprints. Folding and crimping the film also introduces local changes in sensitivity. Keep the surfaces that the film travels over clean to prevent scratching of the film's base or emulsion. A more detailed discussion of longterm storage may be found in The Book of Film Care, KODAK Publication No. H23.
52
ROLLS AVAILABLE
and
Motion picture film emulsions are coated on a 54inchwide continuous web of film base. These 54inch rolls constitute the master stock rolls that are slit into strips during the finishing process. Each master roll is assigned a number, and each strip also has a reference number. After slitting, the strips are perforated and cut to the designated lengths. KODAK and EASTMAN 16 mm camera films used for direct projection are available with magnetic sound striping for use in singlesystem sound cameras. A recording stripe 0.100inch wide is applied along the unperforated edge on the base side and a narrow balance stripe is applied along the perforated edge of the base. KODAK and EASTMAN Motion Picture Camera Films are then wound on cores or spools, the ends are taped, and the wound film is wrapped in black, plastic bags before being packaged in taped metal cans or box bins. The plastic bags protect the film from exposure to light, provide a high degree of cleanliness, and make the film fit snugly inside the can. The tape used on the outside of a film can serves as a seal between the cover and body of the can. This tape is designed to resist the flow of air and moisture so that the newly manufactured film retains its original moisture content. The tape and the can are both marked to identify the contents. A description of the identifying codes on tape, can label, and film appears under FILM IDENTIFICATION, page 63. The "rolls available" block on the data sheet describes forms in which a particular film type is available. The first column gives the catalog number (CAT No.), perhaps the most important piece of information to know when ordering film from Kodak. The catalog number identifies a particular kind of emulsion, film format, and length to our Customer Relations Representatives. For example, CAT No. 124 6636 describes only one film package: 100 feet of EASTMAN Color Negative Film 5247 (35 mm), EI Winding, one row of perfs (1866 pitch), with a film identification number of ECN718. The second column gives the film identification number, a combination of a threeletter film emulsion designation (ECN, in the example above) and a threedigit specification number (718, in this case). The number designates film width; perforation type and format; type of core, spool, or magazine; and winding. This code does not generally refer to the film length. The last two or three columnsDescription, Format (applicable only to films available in multi rank), and Perforation Typeprovide the film length and the information abstracted from the specification number.
53
CORES AND SPOOLS KODAK and EASTMAN Motion Picture Films are available on several types of cores and spools, each appropriate to the design of the equipment in which the films are to be exposed. The films are connected to the core, or spool, in one of the following ways: (1) wound on the core indicates the film is initially started by tightly lapping several convolutions of film around the core. When the film is wound on the core, the core cannot be removed from the film except by unwinding the film; (2) core inserted indicates that the film is initially wound on a collapsible mandrel that is later removed and the core inserted in the cavity of the roll. Thus, the film is not attached to the core. The standard core and spool types for KODAK and EASTMAN Motion Picture Films are shown and described below:
Figure 34
Type T Core16 mm. Figure 34 illustrates a plastic core with a 2inch (51 mm) outside diameter and a 1inch (25.4 mm) diameter center hole with key way and film slot. Normally used with 16 mm films up to 400 feet (122 m) in length, except 100foot (30.5 m) and 200foot (61 m) lengths of camera negative and reversal materials, which generally come on camera spools with integral leaders and trailers for loading under subdued light.
Figure 35
Type Z Core16 mm. A plastic core with a 3inch (76 mm) outside diameter. Contains a 1inch (25.4 mm) diameter center hole with keyway and a film slot. Used with camera and print films in roll sizes longer than 400 feet (122 m). See Figure 35.
Figure 36
Type U Core35 mm. A plastic core with a 2inch (51 mm) outside diameter. Contains a 1inch (25.4 mm) diameter center hole with keyway and a film slot. Customarily used with camera negative, sound, print, and television recording films, and positive films that are used in title cameras. Supplied in a variety of lengths. See Figure 36. 54
Figure 37
Type K Core35 mm. A plastic core with a 3inch (76 mm) outside diameter. Contains a 1inch (25.4 mm) diameter center hole with keyway and a film slot. Used with 2000foot (610 m), 3000foot (914 m), 4000foot (1219 m), and some 1000foot (305 m) lengths of negative, sound, print, and television recording films. See Figure 37.
Figure 38
Type Y Core35 mm. A plastic core with the same dimensions as the Type K Core but made of a stronger material to hold 6000foot (1829 m) rolls of color print film. See Figure 38.
Figure 39
R90 Spool16 mm. A metal camera spool with a 3.615inch (92 mm) flange diameter and a 1 1/4inch (32 mm) core diameter. Square hole with single keyway in both flanges. Center hole configuration is aligned on both flanges. The standard sales lengths for this spool are 100 feet (30.5 m) of acetate base film. Used in cameras such as the Canon and Elmo for double super 8 film and in 16 mm spoolloading cameras. See Figure 39.
Figure 40
R190 Spool66 mm. A metal camera spool with a 4.940inch (125 mm) flange diameter and a 1 1/4inch (32 mm) core diameter. Square hole with single keyway, two offset round drive holes, and one elliptical hole in both flanges. Side 1 and Side 2 markings. Will accept 200 feet (61 m) of acetate base film. See Figure 40. 55
Figure 41
S83 Spool35 mm. A metal camera spool with a 3.657inch (93 mm) flange diameter and a 31/32inch (25 mm) core diameter. Square holes with single keyway in both flanges. Center hole configuration is aligned on both flanges. Intended for 100 feet (30.5 m) of acetate base film. Used with camera negative materials. See Figure 41.
WINDING When a 16 mm roll of raw stock, perforated along one edge, is held so that the end of the film leaves the roll at the top and to the right, it is designated Winding A if the perforations are toward the observer, Winding B if the perforations are away from the observer, as shown in Figure 42. Winding A films are used to make contact prints and are not intended for use in the camera. Winding B is used for camera film, to make optical prints, and on bidirectional printers. NOTE: When requesting singleperforated film on a spool or core that has nonsymmetrical flanges (i.e., a different hole or keyway on either side), you must indicate the hole or keyway closest to the perforations and specify whether the emulsion should be wound in or out.
Figure 42 Winding A Emulsion Side In
Winding B Emulsion Side In
Film for use in 16 mm singlesystem sound cameras is regularly furnished in Winding B on 100foot (30.5 m) and 200foot (61 m) spools. It is also furnished in Winding B on 400foot (122 m) Type T cores and, occasionally, on spools. 56
PERFORATIONS Sizes and Shapes In the early days of 35 mm motion pictures, film perforations were round. Because these perforations were more subject to wear, the shape was changed to that now known as the Bell & Howell (BH) or "negative" perforation. See Figure 43. This modification improved positioning accuracy and was the standard for many years. During this time, 35 mm professional motion picture cameras and optical printers were designed with registration pins that conformed to negative (BH) perforation and are still so designed to this day. Thus, camera films and many laboratory films use the negative (BH) perforations. The high shrinkage of older films on nitrate base made the negative perforation a problem on projection films because of the excessive wear and noise during projection as the sprocket teeth ticked the holdback side of the perforations as they left the sprocket. The sharp corners also were weak points and projection life of the film was shortened. To compensate for this, a new perforation was designed with increased height and rounded corners to provide added strength. This perforation, commonly known as the KS or "positive" perforation, has since become the world standard for 35 mm projection print films. During the period when the production of color prints involved the multiple printing of separation negatives onto a common print film, a third design, known as the DubrayHowell perforation, was introduced. It had the same height as the negative (BH) perforation to maintain the necessary registration but had rounded corners to improve projection life. This perforation is still available for special applications and on certain films (EASTMAN Color Intermediate II Film 5243, for example). Because shrinkage in current films is low, the shorter perforation height poses no projection wear problems. In 1953, the introduction of CinemaScope produced a fourth type of perforation. This widescreen projection system incorporated 35 mm film with perforations that were nearly square and smaller than the positive (KS) perforation. The design provided space on the film to carry four magneticsound stripes for stereophonic and surround sound. Although not widely used now, this perforation is still available on 35 mm EASTMAN Color Print Film. Except for early experimentation, perforation dimensions on 16 mm and 8 mm films have remained unchanged since their introduction. Each type of perforation is referred to by a letter identifying its shape and by a number indicating the perforation pitch dimension. Perforation pitch is the distance from the bottom edge of one perforation to the bottom edge of the next perforation. The letters BH indicate negative perforations, which are generally used on camera films, on intermediate films, and on films used in specialeffect processes. The letters KS indicate positive perforations, which are used on most positive sound recording films and color print films. The letters CS designate the smaller perforations used for projection prints on which additional space must be provided for multiple sound tracks in the CinemaScope process. The designation BH 1866, for example, indicates a film having negative type perforations with a pitch dimension of 0.1866 inch (4.740 mm). 57
Camera films may be perforated along both edges (double perforated) or along only one edge (single perforated). All 35 mm camera films are double perforated. Films for singlepass 16 mm and 8 mm camera use may be single or double perforated. Singleperforated 16 mm films are often magnetically striped for singlesystem sound or post process sound addition. Doubleperforated super 8 and regular 8 film is always suppled in 16 mm width to allow twopass camera operation. Films used in laboratories for intermediate and release prints are supplied in a variety of perforation formats. The letter R preceded by a number designates the number of rows of perforations in a strip (1Rone row, 2Rtwo rows, etc.). Some flexibility is possible in selecting double or singleperforated film. You can use doubleperforated film in cameras having a single pulldown claw. Also, you can duplicate or print footage exposed on doubleperforated film on singleperforation stock if a photographic (optical) or magnetic sound track is to be added to the film. (NOTE: Do not use single perforated film in equipment designed for doubleperforated film.)
Bell & Howell (BH)
Kodak standard (KS)
Figure 43
16 mm
Perforation Type Bell & Howell Dimensions C D H* R
Inches 0.1100 0.0730 0.0820
mm
2.794 1.854 2.08
*Dimension H is a calculated value.
58
Kodak Standard Inches
mm
0.1100 0.0780
2.794 1.981
0.020
0.51
Tolerance ±
16
Inches 0.0720 0.0500 0.010
mm
Inches
mm
1.829 1.270
0.0004 0.0004
0.010 0.010
0.25
0.001
0.03
Perforated two edges
Perforated one edge
Figure 44 Perforation Type and ANSI Number 1R3000 (PH22.12)
1R2994 (PH22.109) Dimension A" B E F G
Inches
mm
0.628 0.2994 0.0355
15.95 7605 0902
Inches
mm
0.628 0.3000 0.0355
15.95 7.620 0.902
2R3000 (PH22.5)
2R2994 (PH22.110) Inches
mm
0.628 0.2994 0.0355
15 95
0.413 0.001
10.49 0.03
7.605 0.902
Inches
mm 15.95 7.620 0.902 10.49
0.628 0.3000 0.0355 0.413 0.001
0.03
Tolerances Inches
mm
0.001 0.0005 0.0020 0.001 —
0.03
0.03
0.8
0.013 0.051 0.03
—
(max) 29.94
Lt
30.00
760.5
762.0
29.94
760.5
30.00
762.0
*This dimension also represents the unperforated width. t This dimension represents the length of any 100 consecutive perforation intervals.
Figure 45 Perforation Type and ANSI Number BH1866 (PH22.93) Dimension A' B E F G
BH1870 (PH22.34|
Inches
mm
Inches
mm
1 377 0 1866
34.975
1.377 0 1870
34.975
4.74
4.75
KS1866 (PH22.139) Inches
1.377 0 1866
KS1870 (PH22.36)
mm
Inches
mm
34 975
1..377
4.740
0 .1870
34.975 4.750
0.079 0999
0.079 0.999
0.079
2.01
25.37
0.079 0.999
2.01
25.37
25.37
25.37
0 001
0.03
0.001
0.03
0.001
0 03
0 999 0.001
2.01
2.01
0.03
Tolerances + Inches
mm
0.001
0.025
0.0005 0.002 0.002 —
0.013
0.015
0.38
0.05 0.05
—
(max) Lt
18.66
474.00
18.70
474 98
18.66
474.00
18.70
474.98
59
Perforation Types 35 mm and 65 mm End Use 1. BH187035 mm BellHowell negative perforations with a pitch measurement of 0.1870" (long pitch), ANSI PH22.931980 2. BH186635 mm BellHowell negative perforations with a pitch measurement of 0.1866" (short pitch), ANSI PH22.931980 3. KS187035 mm and 65 mm KODAK Standard Positive perforations with a pitch measurement of 0.1870" (long pitch), ANSI PH22.139 1980;PH22.1451981 4. KS186635 mm and 65 mm KODAK Standard Positive perforations with a pitch measurement of 0.1866" (short pitch), ANSI PH22.1391980; PH22.1451981 5. DH187035 mm DubrayHowell perforations with a pitch measurement of 0.1870" (long pitch), ANSI PH22.1021980 6. CS187035 mm CinemaScope perforations with a pitch measurement of 0.1870" (long pitch), ANSI PH22.1021980 7. KS187070 mm film perforated 65 mm KODAK Standard Positive perforations with a pitch measurement of 0.1870" (long pitch), ANSI PH22.1191981
16 mm End Use 8. 2R299416 mm film perforated two edges with a perforation pitch of 0.2994" (short pitch), ANSI PH22.1101980 9. 2R300016 mm film perforated two edges with a perforation pitch of 0.3000" (long pitch), ANSI Ph22.1101980 10. IR2994Same as No. 8 except perforated one edge, ANSI PH22.1091980 11. 3R299435 mm film perforated 16 mm with perforation pitch of 0.2994" (short pitch), ANSI PH22.1711980 12. 1R3000Same as No. 11 except with a perforation pitch of 0.3000" (long pitch), ANSI PH22.1711980 13. 3R3000Same as No. 11 except with a perforation pitch of 0.3000" (long pitch) ANSI PH22.1711980
60
Optimum Pitch for Printing Continuous printers used for motionpicture film are designed so that the original film and the print raw stock are in contact (emulsiontoemulsion) with each other as they pass around the printing sprocket, with the raw stock on the outside. To prevent slippage between the two films during printing (which would produce an unsharp or unsteady image on the screen), the original film must be slightly shorter in pitch than the print stock. In most continuous printers, the diameter of the printing sprocket, Figure 46, is such that the pitch of the original must be 0.2 to 0.4 percent (theoretically, 0.3 percent) shorter than that of the print stock. With nitrate film and early safety film, this condition was achieved by natural shrinkage of the original during processing and early aging. However, the substantially lower shrinkage of present safety films makes such a natural adjustment impossible; therefore, film used as printing originals is now manufactured with the pitch slightly shorter than the pitch of the print film. For 35 mm film, the pitch dimensions are 0.1870 inch (4.750 mm) on print film and 0.1866 inch (4.740 mm) on original film; for 16 mm film, they are 0.3000 inch (7.620 mm) on print film, 0.2994 inch (7.605 mm) on original film. For intermediate and print films used to make super 8 prints, the pitch dimensions are 0.1667 inch (4.234 mm) on print film, 0.1664 inch (4.227 mm) on intermediate film. This difference in pitch accounts for about 0.2 percent of the theoretical 0.3 percent; processing and aging shrinkage of the original film before printing usually provides the balance. See the first reference on page 60 for additional information.
Figure 46 SPROCKET
A printing sprocket
Projection Print Aspect Ratios The aspect ratio is the relationship between the width and height of an image. While the image dimensions may vary in size according to projection requirements, the aspect ratio should comply with the cinematographic intent. The industry standard for theatrical motion pictures remained a constant 1.37:1 between the introduction of sound and the introduction of CinemaScope in 1953 when wide screen presentations were developed. While the original stereophonic (fourtrack magnetic) CinemaScope presentation had an aspect ratio of 2.55:1, the flat, or nonanamorphic 61
systems, designed to simulate wide screen images, provided several aspect ratios from 1.66:1 all the way up to and including 2:1. During this uncertain period, release prints were often printed with wider frame lines to emphasize that increased ratios were intended. During printing, the frame lines could be varied by printing the lines in to cover some of the original film image. At the same time, television's demands for feature films increased. However, because the typical television display provides a fixed ratio of 1.33:1, many of the films shown on television, after adjustment to fill the video screen height, lost a substantial part of the image at the edges. See Figure 47. Several approaches to rectifying this incompatibility were tried with various levels of success until the industry came to the current "consensus" that 1.85:1 would be the "normal" theatrical projection ratio but that the print would have an image of greater height so that it could fill a television screen without creating borders. Today, the usual procedure when filming productions for theatrical release and eventual TV showing is to "matte" the camera viewfinder to clearly indicate 1.85:1 and to keep all pertinent action within this area. Nevertheless, the entire 1.37:1 frame is exposed. The cinematographer must make certain no scene rigging, mike books, cables, or lights are included in the expanded area. Subsequent release prints, therefore, contain a sufficient frame height to provide normal telecine transmission. In the theater, the projectionist must use a 1.85:1 aperture plate and exercise some judgment in adjusting the projector framing. This can be done conveniently during the showing of the titles.
CAMERA 1.37:1
1.37:1
Potential image losses when changing aspect ratios
Figure 47
62
TV 1 33 1
1.85:1
FILM IDENTIFICATION Unprocessed Film The label contains the characteristics of up processed film. The elevendigit code on the label in Figure 49 (52471234567) identifies the film type (5247), the emulsion batch number (123), and the number of the roll (4567) from which this strip of EASTMAN Color Negative Film was cut. The emulsion batch number and roll number also appear on the tape sealing the can. The Film Identification code (ECN 718 in this case) gives the emulsion type (ECN or EASTMAN Color Negative Film) and film specification number (718), a code describing width, perforation type and format, winding, and type of core, spool, or magazine. The film width, perforation pitch, and emulsion position and winding type are identified on the label. The filmstrip reference number identifies the location of a particular strip of film cut from the master roll. This number (1 through 38 for 35 mm and 1 through 83 for 16 mm) appears on a sticker affixed to most cans holding 400 or more feet of film. Figure 48 shows such a sticker.
Figure 48
63
HOW TO READ A FILM CAN LABEL Tungsten Rating With no filter, will give indicated speed ratings.
Upper Portion of Label is peelable. It can be placed on film magazine as reminder of product being used.
Daylight Rating With an 85 Filter, will give indicated speed ratings.
Metric Perforation Pitch
Emulsion Position and Winding T y (Emulsion I
Color Bar identifies Film
Emulsion Let Designation a Finished Fil Specificatio
Film Width
Length o f Roll in Meter Perforation Type Identification
Kind of Film
Emulsion Number
Roll Number
Catalog Number
Inch Perrforation Pitch
Film Sizes 65 mm
Figure 49
64
35 mm
16 mm
Length of Roll in Feet
Processed Film The film strip reference number affixed to the can of raw stock film also appears as a latent image on the film itself. It is visible on the processed film between "EASTMAN" and "SAFETY FILM" on the edge print On 35 mm films having multiplerow perforations (used only by processing laboratories to print multiple copies of a film simultaneously), a lowercase letter or letters (a, b, c, etc) appear between "SAFETY" and "FILM" to identify the perforation format of the parent strip and the location of the sub strip within it The combinations of manufacturer's code (an uppercase letter for 35 mm or a trailerend marking for 16 mm), film base data, and edgeprint medium (ink or latent image) are helpful in identifying processed film. If a film data sheet carries a "Film Identification" heading, the uppercase letter of the manufacturer's code will be listed.
Know Your Films Design, manufacture, actual shooting, projection, and storage conditions all influence film performance and selection. First we'll discuss why an onsite test is a good idea. Suppose your test shows that the film stock being considered produces unattractive results under the lights you plan to use to illuminate a few scenes. Will a filter correct the situation? Can you change the lighting? Will another film stock work better for those scenes? Our second topic, filtration, covers the wide range of uses for filters to fill the needs of your unique circumstances. The third section covers the process by which the sound you recorded is combined with your images in the final print. The last two sections explain how to care for the finished films you have to carefully created. Test Exposures Every production presents a unique set of conditions and demands. A full understanding of the job at hand and careful evaluation of the information in the data sheets should give the filmmaker a good idea of how a chosen film stock will respond to most filming situations. Testing reduces any remaining uncertainties and establishes the reaction of a particular film to a unique situation. The variations that make test exposures worthwhile and the technique of interpreting such exposures are the subjects of this section. Testing is one aspect of professional work too often overlooked in practice. When seeking the best possible results, filmmakers should run tests to provide reference points during production and to confirm choices based on previous experience and data sheet information.
65
Here, listed in the order of the time they may occur, are the principle causes of real or apparent changes in speed in all films, and contrast and color balance in color films. Failure to understand these causes can lead to misunderstanding or misinterpretation of photographic results: • Slight manufacturing variations among different emulsion batches • Adverse storage conditions before exposure • Scene illumination of incorrect or mixed color quality • Differences in film sensitivity with changes in illumination level and exposure time • Variations in equipment (lenses, shutters, exposure meters, etc) • Adverse storage conditions between film exposure and processing • Nonstandard processing conditions • Nonstandard viewing conditions • Differences in personal judgment All except the first are beyond the scope of manufacturing control and cannot be predicted accurately from the data sheets. Furthermore, the variations encountered in practical use are apt to be a great deal larger than those permitted by manufacturing tolerances. These are the basic reasons why you should make a test exposure whenever speed and colorbalance are important. Test exposures are necessary for reversal materials that will be projected directly after processing more so than for negative or printed reversal materials because density and colorbalance adjustments cannot be made during printing. Most professionals realize the perishable nature of sensitized materials and are careful to avoid subjecting films (especially color) to extreme heat and humidity, either before or after exposure. The other factors listed are equally important, however, even if not equally familiar. None should ever be overlooked when choosing a film or attempting to explain an unexpected result. Two or more causes of variation may influence results at the same time. Often the effects are additive, and minor single variations will, when combined, produce noticeable results unless proper compensation is made in advance. Only a test exposure under the practical conditions of use will furnish this information. To Provide a Reference Point A speed variation of 1/3 stop, and sometimes more, usually passes unnoticed when blackandwhite film is projected. In a color film, where the performance of each emulsion layer is evaluated in terms of the other two, a much smaller variation in the relative speed of any one layer is evident to the user. Coating thickness is a manufacturing variable that provides an excellent illustration of the technical accuracy maintained in making color films. Tests have shown that the thickness of each emulsion layer must be controlled within 4 or 5 percent; any larger variation would by itself use up the entire colorbalance tolerance available. 66
Since a typical color emulsion is only 3 ten thousandths of an inch thick, so only 15 millionths of an inch variation is allowable. And this kind of accuracy is maintained in making successive coatings on a thin, flexible base in the dark! Every effort is made to achieve the greatest possible uniformity in the manufacture of Kodak films, but within such close tolerances minor variations are unavoidable. Of course, variations are smallest among films of the same emulsion number. In any case, test data obtained under actual production conditions is recommended to supplement the manufacturer's data. At Kodak, the standardization of manufacturing operations is supplemented by an extensive testing and qualitycontrol program. Only film produced within narrow tolerances of the production aim point is shipped from the manufacturing plant. The actual sensitometric tolerances tested include speed, fog, contrast, colorcontrast match, and maximum density. Production tests are made at normal room temperature with illuminants equivalent in color quality to tungsten (3200 or 3400 K) lamps for tungsten films and to average sunlight plus skylight (5500 K) for daylight films. They are exposed at times considered representative of the major applications for the films. In all cases, films are processed in accordance with process specifications. Physical characteristics such as curl, perforation pitch, weave, tensile strength, freedom from scratches, etc., are also carefully controlled. With EASTMAN and KODAK EKTACHROME Films, the permitted colorbalance variations, tested under normal recommended use, fall approximately within the range correctable by a CC10 filter in the camera exposure. In the case of negative films, normal colorbalance variations fall within a range for which adjustment can easily be made in the printing process. The careful cinematographer should make practical picture tests on new film batches with the exposure and filtration to be used for the rest of the production. These tests will help to determine if any additional filtration and exposure adjustments are needed. For Locations with Unfamiliar Lighting Filmmakers are well aware that color films are balanced in manufacture for exposure to light of a certain color quality. Color negative film offers considerable latitude because some adjustments for color balance you can make during printing. Even reversal materials that will be printed offer some latitude because of the printing step. However, when a reversal material isn't going to be printed, you must make compensation if the light source differs in color quality from that for which the film is balanced. Even the "correct" light may be changed appreciably in color quality as it passes from source to subject to film. Discolored or dirty reflectors and camera lenses with a color tint can change color quality. Furthermore, the color quality of tungsten and fluorescent lamps can change with age and voltage fluctuations. Lighting from mixed sources will also change color renderings.
67
To Establish a Reference with You and Your Laboratory Different laboratories can produce noticeable variations in image quality and effective film speed, and from time to time variations can be noted at a single laboratory. Typical processing can result in speed variations of plus or minus 1/2stop and colorbalance variations on the order of ±CC10 filter. Tests processed by your chosen laboratory serve as a base in all future discussions with the laboratory. To Evaluate Specific EndUse Appearance The conditions under which film is viewed have a marked effect on the apparent color quality of the picture. For critical applications, test film should be projected and evaluated under the specific conditions in which it will be used. The locations of the projector, the viewer, and the screen can affect the image quality dramatically. To Determine the "Look" of the Finished Job Because the viewers' reactions to a projected image involve their psychological responses, a projected image can never be "perfect" in any simple sense. Like all photographic and electronic imaging systems, Kodak color films exhibit small color differences between the image and the subject itself when they are critically compared. Usually these differences are insignificant, but cinematographers have to judge whether the "look" of the film is consistent with their intentions and with the nature of the subject. Since the manufacturer's evaluation of color balance is determined from picture tests judged by a number of observers, it is obvious that an individual cinematographer, producer, or laboratory may prefer a color balance different from one judged desirable by the manufacturer. Because the manufacturer can never judge color balance appropriately for all tastes and all extremes of working conditions, critical work should be preceded by tests made as closely as possible to the conditions of final use, if possible, on the actual subject. You should always make the test on film of the same emulsion number as that to be used for the final exposure and kept under similar conditions before and after exposure. The exposure time, light source, and processing conditions should also be identical with those planned for the final work. To Check Specific Color Reproduction With only three dyes, color films are able to produce a pleasing rendering of most colors. Occasionally, though, some colors present special difficulties in accurate reproduction, even though the film has been manufactured, stored, exposed, and processed correctly. Fortunately, the conditions that produce these effects are not common. Since a large majority of all photographs include people, the reproduction of flesh tones is a primary consideration in the design of a color film. Also important are the reproduction of neutrals (whites, grays, and blacks) and the reproduction of common "memory" colors, such as blue sky, green grass, etc. Because films are designed to reproduce these colors properly under a variety of conditions, some other colorssuch as shades of chartreuse, lime, pink, and orangemay reproduce less well. (It is possible to
68
design a film that would improve the reproduction of these other colors, but only at the expense of generally more important flesh tones, sky, grass, etc.) More noticeable difficulties can be encountered because color films do not have exactly the same color sensitivities as the human eye. For most subjects, the three lightsensitive layers of the film do not have to "see" the subject exactly the same way the human eye does. In most cases, the differences are scarcely noticeable. Sometimes, though, the differences between film sensitivity and visual sensitivity produce unwelcome results. Since color films are sensitive to ultraviolet radiation, a substance reflecting ultraviolet energy will reproduce bluer on film than it looks to the eye. If it is blue to begin with, this effect is of little or no consequence. With other colors, however, the additional blueness may neutralize the original color or even make it appear blue. Neutral and nearneutral colors are more apt to be affected by such a shift, because their saturation is low. For example, a black tuxedo made of synthetic material may appear blue. An ultraviolet absorbing filter, such as a KODAK WRATTEN Gelatin Filter No. 2B, over the lens or over the light source when practical can reduce this effect. Closely related is the effect of ultraviolet fluorescence. Some fabrics absorb ultraviolet radiation and remit it in the nearblue (shortest wavelength) portion of the visible spectrum. Since the eye is not very sensitive in this part of the spectrum, the effect may not be readily apparent until a photograph of the subject is viewed. An analogous visual effect is created by black light which makes special paints, some fabrics, etc, glow in the dark. Under an ultraviolet lamp, any fabric containing brighteners will fluoresce, but many white fabrics contain brighteners introduced during manufacture or laundering to give them a whiter appearance. Examination of any suspect fabrics under an ultraviolet source will generally indicate whether there will be a fluorescence problem. In this case, a filter over the lens does not help; however, an ultraviolet absorber over the light source may prove helpful. A photographic test is the best way to determine whether problems with reproduction in the ultraviolet range should be anticipated. Perhaps most troublesome are the color reproduction problems sometimes called anomalous reflectance. They arise from high reflectance at the far red and infrared end of the spectrum, where the eye has little or no sensitivity. The heavenly blue morning glory and ageratum flowers are examples of colors occurring in nature that reproduce poorly because color films are much more sensitive to the far red than the eye. Among artificial materials, some classes of organic dye are notable examples of high reflectance in the far red. These dyes are currently very popular with fabric manufacturers because they are relatively inexpensive and work well with synthetic materials. While the high reflectance of these dyes in the far red and infrared can be found in all colors, its effect is most noticeable in medium to dark green fabrics, where the photographic effect of the far red reflectance is to neutralize the green, making it appear browner. You can identify high reflectance at the far end of the spectrum can be identified by use of a deep red filter such as a KODAK WRATTEN Gelatin Filter No. 70. If the materials are examined under a tungsten light, a green naturalfiber material will appear black, whereas a synthetic material with 69
high reflectance in the far red will appear much lighter. Because the judgment is quantitative, a sample of a green fabric known to reproduce well should be compared with the test fabric under the filter. If the test fabric appears distinctly light in a sidebyside comparison through the No. 70 filter, you should expect a reproduction problem. Even then, confirmation by means of a photographic test under actual working conditions is advisable if circumstances permit
70
FILTRATION White light is the sum of all the colors of the rainbow; black is the absence of all these colors. For practical purposes, we can consider white light as composed of equal amounts of three primary light colorsred, green, and blue. For example, if green and red are subtracted, we see blue. We see many more colors in nature than these three because absorption and reflection of the primaries are rarely complete. Our perception of a color is influenced by the surrounding colors and brightness level, the surface gloss of an object, and any personal defects in our color vision. Different films also see colors differently due to differences in spectral sensitivity. Filtration used with blackandwhite films can control the shades of gray to obtain a technically correct rendition or to exaggerate or suppress the tonal differences for visibility, emphasis, or other effects. Filtration with color films can change the color quality of the light source to produce proper color rendition or to create special effects. Colors as Seen in White Light
Colors of Light Absorbed
Red Blue Green Yellow (redgreen) Magenta (redblue) Cyan (bluegreen) Black
Blue and green Red and green Red and blue Blue
White Gray
Green Red Red, green, and blue None Equal portions of red, green, and blue
Filters always subtract some of the light reflected from a scene before it reaches the film plane in the camera. A red filter then is not "red" but rather a filter that absorbs blue and green. Similarly, a yellow filter is one that absorbs blue light. A yellow sunflower absorbs blue light and reflects the other parts of white lightred and green, which we see as yellow (lack of blue).
71
Filters Useful with All Camera Films Polarizing Filters Polarizing filters (also called polarizing screens) are used to subdue reflections from surfaces such as glass, water, and polished wood, and for controlling the brightness of the sky. By reducing glare, polarizing filters also increase color saturation. Using a polarizing filter to control the brightness of the sky has several advantages over color filters: (1) The color rendering of foreground objects is not altered. (2) It is easy to determine the effect produced by the polarizing filter by checking the appearance of the image in the viewfinder (for cameras equipped with reflextype viewfinders), or by looking through the filter when it is held at the same angle as used on the camera. (3) Other filters can be used with a polarizing filter to control the color rendering of objects in the foreground, while the polarizer independently controls the brightness of the sky. The amount of polarized light from a particular area of the sky varies according to the position of the area with respect to the sun, the maximum occurring at an angle of 90° from the sun. Panning the camera, therefore, should be avoided with a polarizer because the sky will become darker or lighter as the camera position changes. The sky may appear lighter than you would expect for these reasons: • A misty sky does not photograph as dark as a clear blue sky. You can't darken an overcast sky by using a polarizing filter. • The sky is frequently almost white at the horizon and shades to a more intense blue at the zenith. Therefore, the effect of the filter at the horizon is small, but it becomes greater as you aim the camera upward. • The sky near the sun is less blue than the surrounding sky and, therefore, is less affected by a filter. When you begin making exposures with a polarizing filter, be sure to remember that this filter has a minimum filter factor of 2.5 (increase exposure by 1 1/3 stops). This factor applies regardless of how the polarizing screen is rotated. In addition to this exposure increase, you must make any exposure increases required by the nature of the lighting. For example, for the darksky effect, the scene must be sidelighted or toplighted, so it will be necessary to add approximately 1/2stop exposure to the 1 1/3 stop increase required by the polarizing filter factor. Give an additional 1/2stop exposure when you use a polarizing filter to eliminate reflections from subjects; reflections often make objects look brighter than they really are. See Figure 50.
72
Figure 50
A polarizer can eliminate reflections on non metallic surfaces.
Neutral Density Filters Neutral density filters, such as the KODAK WRATTEN Neutral Density Filter No. 96, reduce the intensity of light reaching the film without affecting the tonal rendition of colors in the scene. Neutral density filters make it possible to film in bright sunlight using highspeed films without having to use very small lens openings. In blackandwhite motionpicture photography, KODAK WRATTEN Gelatin Filters No. 03N5 and 8N5 permit the use of a larger lens opening for depthoffield reduction. These filters combine a neutral density of 0.5 with the blue and ultraviolet correction capability of WRATTEN Gelatin Filters No. 3 and No. 8, respectively. In color motion picture photography, You can use combination filters, such as KODAK WRATTEN Gelatin Filters No. 85BN3 and 85BN6, to convert the color temperature from 5500 K (daylight) to 3200 K (professional tungsten lighting), and at the same time, obtain neutral densities of 0.3 and 0.6. Since a 0.3ND filter causes a onestop reduction in exposure, these filters require, respectively, one and two stops of additional exposure.
KODAK WRATTEN Neutral Density Filter No. 96
73
Filters for BlackandWhite Films KODAK WRATTEN Gelatin Filters are used with a wide range of blackand white films for many purposes. They can emphasize clouds, reduce the brightness of blue sky and water, penetrate haze in distant landscapes, increase tonal contrast between colored objects, and produce special effects such as simulated night scenes. The filters used in blackandwhite work fall into three main types: (1) Correction filters change the color quality of the exposing light so that the film records all colors at approximately the relative brightness values seen by the eye. (2) Contrast filters change the relative brightness values so that two colors that would otherwise record as nearly the same shade of gray will have decidedly different brightness in the picture. (3) Haze filters reduce the effects of aerial haze. Correction Filters Most panchromatic emulsions have a high sensitivity to both ultraviolet and blue radiation. Because this sensitivity is dissimilar to the spectral sensitivity of the eye, blue or violet subjects are often overexposed and rendered too light on the final print. For example in location work, correction filters are often used to overcome an apparent lack of contrast between blue sky and white clouds. At the red end of the spectrum, certain higher speed panchromatic films possess a marked red sensitivity that, unless compensated for, tends to distort the rendering of red subject matter. Deliberate overcorrection is sometimes done to achieve special effects. Foliage looks slightly darker than we expect when it is photographed on blackandwhite film without a filter. By using a yellow or yellowgreen filter to absorb some of the unwanted blue and red light, you can record foliage in its proper gray tone. This may seem to imply a contradiction: If a filter subtracts light, there will be less density on the negative and the print will be darker, so how does the filter make foliage lighter? Actually, the filter darkens the rendering on the print of the color it absorbs, thus making the colors it transmits lighter by comparison. This becomes apparent when the negative is correctly printed. Contrast Filters Used with blackandwhite films contrast filters change the relative contrasts between two objects that would normally photograph as nearly the same shade of gray. The following guideline will help you choose contrast filters: A filter transmits its own color, making that color lighter in a blackand white print. To make a color darker, use a filter that will absorb that color. If you use a No. 25 red filter, which transmits the red of the geranium blossoms and absorbs the green of the grass, the geraniums will be light and the grass dark in your print Since you probably think of the flowers as being brighter than the grass, this print may look natural to you. But if you use a No. 58 green filter, which absorbs the red of the geraniums and transmits the green of the grass, you'll get the opposite result dark flowers and light grass. You can also underexpose the film when using a contrast filter to simulate a night effect under daylight conditions; use orange and red filters, such as KODAK WRATTEN Filter Nos. 23A, 25,29, or 72B. 74
The color filter circle, Figure 51, will help you decide what filters to use to lighten or darken the graytone rendering of most colors. The No. 58 filter is green, for example, which lightens the graytone rendering of green, yellow, and bluegreen, and darkens the rendering of orange, magenta, and red. The filter factors given are often different for tungsten and for daylight because tungsten light contains relatively more red light while daylight contains more blue. Haze Filters The effects of haze can be reduced by filtering out some of the blue and ultraviolet light. Yellow filters, commonly used for haze penetration and darkening of the sky, are KODAK WRATTEN Filters No. 3, 8,12, and 15, in order of increasing absorption. For further darkening of the sky and increased haze penetration, use filters ranging from light orange to deep red, such as filters No. 21, 23A, 25 and 29. These filters absorb varying degrees of blue light and green light.
Figure 51
'For a graytone rendering of colors approximating their visual brightnesses.
Note: If conditions require long time exposures, corrections for reciprocity effect in addition to the corrections for the filter factor may be necessary.
Filters for Color Films In exposing color films and in making prints and intermediates, there are a number of conditions under which you can obtain good color rendition through the use of correcting filters. Daylight and artificial light differ from one another in spectral quality and are individually subject to considerable variation. When the actual light is different from that specified for a particular film, correction filters can adjust the color quality of the illumination to that for which the film is balanced. Data sheet tables are usually a reliable guide to the right filters for obtaining optimum color balance and are especially useful as a starting point from which to run tests. However, they cannot cover all such variables as 75
high or low voltage, aging of lamps, or color contribution of diffusers. Colortemperature meters measuring the three primary colors provide an accurate method of determining the spectralenergy distribution of light sources as they relate to the sensitivities of the three layers in color films. Such meters as the Spectratricolor meter and the Minolta 3 color meter, while costly, provide the user an excellent means of finding the actual spectral distribution. Twocolor meters (much less costly) show the balance between the red and blue light, and are adequate to indicate the spectral distribution of light sources having a continuous energy distribution across the spectrum (such as an incandescent light). They are not satisfactory for sources (such as fluorescent lights) having a skewed or discontinuous distribution. Some meters give a choice of correcting the balance either with color balancing and conversion filters or with color compensating filters. In most instances, making the main correction with color compensating filters requires many filters, while correcting with light balancing and conversion filters requires two at the most. Because the addition of many filters over a camera lens increases flare and decreases sharpness, color temperature (red blue) correction is best made with light balancing and conversion filters and greenmagenta adjustment is best made with color compensating filters.
Selecting Filters for Correcting Color Temperature The color quality of some illuminants can be expressed in terms of color temperaturea measure of the light irradiated by an idearadiator, that is, a black body heated to incandescence. When the visual color of the illuminant is the same, or nearly the same, as that of the ideal radiator at a given temperature, the illuminant color is described in terms of the corresponding temperature of the ideal radiator, which is expressed in degrees Kelvin (K). NOTE: Do not confuse sunlight with daylight. Sunlight is the light of the sun only. Daylight is a combination of sunlight plus skylight. The values given are approximate because many factors affect color temperature. Outdoors, the sun angle and the conditions of sky, clouds, haze, or dust particles will raise or lower the color temperature. Indoors, tungsten bulbs are affected by age (and blackening), voltage, type of reflectors and d iffusersall of which can influence the actual color temperature of the light. Usually, a change of 1 volt equals 10K. But this is true only within a limited voltage range and does not always apply to booster voltage operation since certain bulbs will not exceed a certain color temperature regardless of the increase in voltage.
76
Color Temperature for Various Light Sources Artificial Light Degrees Kelvin
Source Match Flame Candle Flame 40Watt Incandescent Tungsten Lamp 75Watt Incandescent Tungsten Lamp 100Watt Incandescent Tungsten Lamp 200Watt Incandescent Tungsten Lamp 1000Watt Incandescent Tungsten Lamp 3200 K Tungsten Lamp Molard "Brute" with Yellow Flame Carbons and YF101 Filter (approx) "C.P." (Color Photography) Studio Tungsten Lamp Photoflood and Reflector Flood Lamp Daylight Blue Photoflood Lamp White Flame Carbon Arc Lamp HighIntensity Sun Arc Lamp Xenon Arc Lamp
1,700 1,850 2,650 2,820 2,900 2,980 2,990 3,200
3,350 3,350 3,400 4,800 5,000 5,500 6,420
Daylight Source Sunlight: Sunrise or Sunset Sunlight: 1 Hour after Sunrise Sunlight: Early Morning Sunlight: Late Afternoon Average Summer Sunlight at Noon (Washington, DC) Direct Midsummer Sunlight Overcast Sky Average Summer Sunlight (plus blue skylight) Light Summer Shade Average Summer Shade Summer Skylight Will Vary from
Degrees Kelvin 2,000 3,500 4,300 4,300 5,400 5,800 6,000 6,500 7,100 8,000 9,500 to 30,000
77
Light Source Conversion with Filters To evaluate filter requirements for the conversion of light sources, it is helpful to use the reciprocal of the color temperature. The concept of expressing color temperature in reciprocal form is useful because a given sum of reciprocal units corresponds approximately to the same color difference for most visibly emitting sources (in the range from 1000 K to 10,000 K). The reciprocal color temperature is commonly multiplied by 1,000,000 to give numbers of convenient size. The values obtained by this operation have, in the past, been called microreciprocal degrees or "mireds." 1,000,000 x I Recently, the term reciprocal megakelvins (MK 1 ) has been used to replace mireds. The reciprocal color temperature expressed in reciprocal megakelvins has the same numerical value as with mireds, but the value is arrived at by first expressing the color temperature in megakelvins (1 MK = 1,000,000 K) and taking the reciprocal. For example, the reciprocal color temperature for a 6000 K source is 1/0.006 MK = 167 MK1 Filters such as KODAK Light Balancing Filters and KODAK WRATTEN Photometric Filters modify the effective color temperature, hence the reciprocal color temperature, of any light source by a definite amount. Each filter can be given a visual shift value that is defined by the expression
where T1 is the color temperature of the light through the filter (both values expressed in megakelvins). Remember that the concept of color temperature relates to the response of the visual system. To match the actual response of films as opposed to the response of the eye, some filters are designed empirically to fit existing photographic requirements. These filters may or may not provide a visual shift that relates to the measured photographic effect. The table on page 83 give filters that provide the desired photographic result when used for the conversion indicated. The shift value given is a nominal value defined by the equation
and is not a measure of the visual shift that might actually be computed for the filter. A new concept termed photographic color temperature is being developed. If this method proves viable, reporting additional filter data in terms of photographic effect should provide greater assistance in the choice of appropriate filters for photography under a wide range of illuminants. 78
The light source conversion nomograph shown in Figure 52 is designed to simplify the problem of selecting the proper conversion filter. The original light source, T1, is listed in the left column and covers the practical range of color temperatures from 2000 to 10,000 K. The righthand column lists the color temperature of the light through the filterthat is, the converted source, T2. The center column shows the scale of reciprocal megakelvin (MK 1 ) shift values. To find the shift value and consequently the filter required for a particular conversion, it is only necessary to place a straight edge on the points corresponding to the color temperature of the available source, T1, and the desired color temperature of the filtered source, T2, respectively. The straightedge crosses the center column and indicates the reciprocal megakelvin shift value of the required filter. The zero point on this column indicates that no filter is required, values above zero point (+) require yellowish filters, and those below the zero point () require bluish filters. Filters can also be combined, the desired combination being calculated by adding the (MK1) shift values of the filters, with due regard to the sign. If you use more than one filter, remember that the illumination loss and flare due to reflection of the multiple surfaces may become considerable.
Reciprocal Color Temperature (MK1) for Color Temperatures from 2000 K to 6900 K* K
0
100
200
300
400
500
600
700
800
900
2000 3000 4000 5000 6000
500 333 250 200 167
476 323 244 196 164
455 312 238 192 161
435 303 233 189 159
417 294 227 185 156
400 286 222 182 156
385 278
370 270 213 175 149
357 263 208 172 147
345 256 204 169 145
217
179 152
Value • s in reciprocal megakelvins (MK1) are equal numerically to values in "mireds."
Light Balancing Filters Color motion picture films are balanced in manufacture for use either with tungsten light sources (3200 K, type B, or 3400 K, type A) or with illumination of daylight quality (5500 K). KODAK Light Balancing Filters are used over the camera lens to enable the photographer to make minor adjustments to the light reaching the film. If the required colorbalance adjustment is small, a single bluish filter of the No. 82 series, or a single yellowish filter of the No. 81 series, will be adequate. KODAK Light Balancing Filter No. 82 is intended, in effect, to raise color temperature by 100 K, the 82A by 200 K, the 82B by 300 K, and the 82C by 400 K. Those of the No. 81 series (91, 81 A, 81B, 81C, 81D) are intended to reduce color temperature by 100 K steps. For greater color correction, combine two filters in the same series.
79
Conversion Filters If still greater corrections in color are required, you can use light balancing filters and conversion filters. Use conversion filters over the camera lens to make significant changes in the color temperature of illumination (e.g., daylight to artificial light).
Limits to Color Temperature Measurement Color temperature refers only to the visual appearance of a light source and does not necessarily describe its photographic effect Although some light sources emit strongly in the ultraviolet region of the spectrum, the color temperature of such a source does not measure this portion of the emission because the eye is not sensitive to radiation below 400 nm. Since a film is usually sensitive to ultraviolet radiation, a scene can record overly blue unless special corrective means are used to filter out the ultraviolet. Also, color temperature does not take into account the spectral distribution of a light source. Unless the light source has a similar spectral distribution to that of a black body radiator (e.g. various types of tungsten filament lamps), its effective color temperature alone may not be reliable as a means of selecting a suitable filter for adapting the source for color photography. Fluorescent lamps, for example, do not have the continuous, smooth spectraldistribution curve that is characteristic of a tungsten filament source. Although two different light sources may be described as having the same color temperature, the photographic results obtained with each may be quite different.
UltravioletAbsorbing and HazeCutting Filters Photographs of distant landscapes, mountain views, snow scenes, scenes over water, and sometimes aerial photographs in open shade made on color films balanced for daylight are frequently rendered with a bluish cast This is caused by the scattering of ultraviolet radiation to which the film is more sensitive than the human eye. KODAK WRATTEN Filter No. 1A (skylight filter) absorbs ultraviolet light By placing this filter over the lens, you can reduce the bluish cast and slightly penetrate the haze.
80
KODAK Light Balancing and Conversion Filters for Color Films KODAK Light Balancing Filters
Conversion Filters
"These values are approximate For critical work, they should be checked by practical test, especially if more than one filter is used
81
NOMOGRAPH FOR LIGHT SOURCE CONVERSION
The nomograph can be used to find the shift value for a particular conversion by placing a straightedge from an original source (T1) to a second source (T2). The shift value can be read on the center line. Use of the nominal shift values for filters shown on tables (page 81) will allow choice of fillers that approximate the necessary correction. Shift values are algebraically additive; filters can be combined to achieve the required shift
Figure 52
82
Color Compensating Filters for Color Correction A color compensating (CC) filter controls light by attenuating principally one or two of the red, blue, or green parts of the spectrum. You can use them singly or in combination to introduce almost any desired color correction. Use CC filters to make changes in the overall color balance of pictures made with color films, or to compensate for deficiencies in the spectral quality of the light to which color films must sometimes be exposed. Such corrections are often required, for example, in making color prints or in photography with unusual light sources. If the color balance of a test is not satisfactory, the extent of filtering required to correct it can be estimated by viewing the test print through color compensating filters. KODAK Color Compensating Filters have excellent optical quality and are suitable for imageforming optical systemsover the camera lens, for example. However, because they are gelatin filters, they are very susceptible to scratches and fingerprints, both of which can affect optical quality to a serious degree. Color compensating filters are available in several density values for each of the following colors: cyan, magenta, yellow, red, green, and blue. The density of each color compensating filter is indicated by the numbers in the filter designation, and the color is indicated by the final letter. In a typical filter designation, CC20Y represents a "Color Compensating Filter with a density of 0.20 that is Yellow." The densities of color compensating filters are measured at the wavelength of maximum absorption (i.e., the density of a yellow filter is given for blue light). That's the reason the term peak density is used in the table. The density values do not include the density of the gelatin on which the filter dye is coated, nor do they include the density of the glass in which a filter may be mounted. The standardized density spacing of these filter series (5,10,20,30,40, 50 in each color) helps predict the photographic effects of filter combinations. The red, green, and blue filters each absorb two thirds of the visible spectrum; the cyan, magenta, and yellow filters each absorb one third of the spectrum. In the red, green, and blue series, each filter contains the same dyes in approximately the same amounts as the two corresponding yellow and magenta, yellow and cyan, or magenta and cyan filters. Combining Color Compensating Filters The determination of filter combinations can usually be simplified by thinking of all the filters in terms of the subtractive colors: Red (absorbs blue and green) = yellow (absorbs blue) + magenta (absorbs green) Green (absorbs blue and red) = yellow (absorbs blue) + cyan (absorbs red) Blue (absorbs green and red) = magenta (absorbs green) + cyan (absorbs red)
83
The following method of calculation is recommended: 1. Convert the filters to their equivalents in the subtractive colors—cyan, magenta, and yellow—if they are not already of these colors. For example, 20R = 20M + 20Y. 2. Add like filters together. For example, 20M + 10M = 30M. 3. If the resulting filter combination contains all three subtractive colors, cancel out the neutral density by removing an equal amount of each. For example, 1OC + 20M + 20Y = 10M + 10Y + 0.10ND (neutral density, which can be eliminated). 4. If the filter combination contains two different filters of equal density, substitute the equivalent single red, green, or blue filter. For example, 10M+10C = 10B. Exposure Allowance for Filters You must make filters absorb light. You must increase exposure for this loss of light. The published exposure increases for KODAK Color Compensating Filters (see below) provide a rough guide to the exposure adjustments required for a single filter. To determine the exposure increase for two or more filters of different colors run practical tests using initially the sum of the suggested increases for the individual filters. KODAK Color Compensating Filters
"These values are approximate. For critical work, they should be checked by practical tests, especially if more than one filter is used. Similar KODAK Color Printing Filters (Acetate) are available.
t
84
Filters for Color Printing Motion picture printers used for printing color films are generally equipped with highwattage lamps, making it necessary to insert a heatabsorbing glass to protect the mirrors and filters in the printer optical system from damage. Use a dichroic heatreflecting glass or a heatabsorbing filter. The Heat Absorbing Filter No. 2043 (4 mm) now used in many laboratories is satisfactory. It is available from Kodak. An ultravioletabsorbing filter may also be required, as specified on the data sheets. KODAK Color Printing Filters, listed in the table below, are made on an acetate film base and are used singly or in combination for color correction of light sources in subtractive color printing. Color printing (CP) filters are similar to color compensating (CC) filters in that they control principally the red, green, or blue parts of the visible spectrum; unlike CC filters, CP filters cannot be used in the imageforming beam if optimum quality is desired. See KODAK Publication No. B3, Handbook of KODAK Photographic Filters, for more technical information concerning the filters discussed in this section. KODAK Color Printing Filters
85
MOTIONPICTURE SOUND RECORDING A Brief History of Sound Sound was introduced to the movies in 1927 with Al Jolson's The Jazz Singer. In 1977, the motion picture industry celebrated the 50th anniversary of the talkies. 1920's The very first sound was produced in the early 1900's from a phonograph disk running in mechanical synchronism with the picture at 33 1/3 RPM. Obvious synchronization problems requiring the constant attention of the projectionist led to a system which allowed the picture and sound track to be printed together on the same piece of film. 1930's Two photographicsound recording systems evolved—variabledensity and variablearea. Variabledensity meant that the density of the sound track varied in accordance with the audio signal. Variablearea meant that the width of the clear area of the track varied with the signal. Also, there were several different types of variablearea tracks—the earliest unilateral, the improved bilateral and dualbilateral and the special pushpull tracks. Because of the complexities of pushpull tracks, they were used for inhouse operations, not released. Only on picture, the 1941 version of Walt Disney's Fantasia, was released with pushpull tracks, and then only as a special road show performance where Disney technicians had complete control. 1940's The primary shortcoming of photographic sound tracks was (and still is) noise. Early in their use, schemes were devised for noise reduction. Over the years, many variations of both variable density and variablearea tracks were developed to increase their dynamic range. This need for greater sound level led to the abandonment of variable density in favor of the higher output variablearea recording. The added realism of stereophonic sound challenged engineers. In the late 1930's, Bell Labs developed a stereo system with four variablearea tracks on 35 mm film and in 1941, Fantasia was released as the first commercial stereo release. 1950's The 1950's brought widescreen pictures—most using multiple magnetic tracks for stereo sound. The driving force was more realistic and exciting theater entertainment to counter the home TV threat to their business. In late 1952, a threecamera, threeprojector, ultrawide screen format was introduced. Its seven sound tracks were on a separate film run synchronously with the picture. In 1953, Fox released The Robe in CinemaScope—a 2.35:1 wide screen picture from a standard 35 mm print with four magnetic tracks, three for wideband audio and a narrow track for surround sound. ToddAO, the company which invented 70 mm 6track 86
magnetic sound tracks, revolutionized the industry with its 70 mm release of Oklahoma in 1955. This doublewidth film not only gave the very best widescreen picture, but its six magneticsound tracks produced stereo sound of superb quality. Many other widescreen contenders offering improved quality or lower cost came and went—CinemaScope 55, MGM Camera 65, Cinemiracle, Technirama, and Vista Vision. 1960's and 1970's In the 1960's and early 1970's, 70 mm 6track magnetic sound and 35 mm CinemaScope fared the best However, the laws of economics did catch up with CinemaScope. Ninety percent of these prints were released with no magnetic tracks, only a monaural optical track. Of the remaining 10 percent that had magnetic tracks for stereo, nearly all also had a 1/2 width optical sound track nudged in so that the print could be played in theaters without magnetic stereo capability. The reason was simple. The addition of magnetic stripes and recording four tracks on each print increased their cost from 50 to 75 percent. Also, superior magnetic sound required scrupulous and costly maintenance of the magnetic sound reproducers. These cost pressures caused engineers to take a close look at optical sound. If they could substantially improve the frequency response and signaltonoise ratio of an optical track, several tracks could be recorded in the space used for one. They could produce stereo sound without the added print costs of magnetic tracks. In mid1965, Ray Dolby from Oregon, then living and working in England, developed a noise reduction system for magnetic reduction in magnetic recording that was adopted immediately in the music industry. In 1972, Dolby noise reduction was introduced into motionpicture sound recording, but for monaural sound, not stereo sound. Dolby Laboratories, spurred by a Kodak employee, Ron Uhlig's success with 2track, 2channel stereo sound for 16 mm film, developed a 2track stereo variablearea system with complete compatibility. Theaters converted to decode Dolby tracks could enjoy the low noise, relatively widefrequency range stereo reproduction and also get acceptable monaural sound when playing a standard Academy mono print. Also, Dolbyencoded stereo prints would yield acceptable monaural reproduction on unconverted projectors on theaters not equipped for stereo. In 1974, two pictures were released with Dolby Stereo VariableArea (SVA) tracks; in 1976, four pictures; and by 1978,25 pictures. Over 900 theaters worldwide were equipped to reproduce Dolbyencoded SVA tracks by 1979. At that time, it cost between $10,000 and $15,000 to add Dolby SVA to theaters already equipped to play stereo from 4track CinemaScope or from 6track 70 mm prints. For theaters only able to play monaural tracks, these costs increased to between $15,000 and $25,000. All for the attraction of Dolby Stereo on the marquee, but that's proved to be a substantial attraction to the many theaters who invested in Dolby. Other contenders for this marketplace were Colortek, ToddAO/Nuoptix, Universal with its Sensurround, 20th CenturyFox with their Fox Sound 360, and Pacific Theaters with their drivein bilingual presentation of Star Wars. 87
Through it all, three formats have withstood the test of time: • 35 mm Monophonic Photographic Sound Tracks or Academy Tracks—a standard format since 1927. These are bilateral or dualbilateral variable area tracks. The term Academy was coined because of standardization efforts made in the late 1930's by a group at the Academy of Motion Picture Arts and Sciences. • 35 mm Stereophonic Photographic Sound Tracks with Dolby Noise Reduction—the most common 35 mm format today. Dolby calls them SVA or Stereo VariableArea Tracks. • 70 mm Magnetic Sound Tracks—a format used in specialized theaters who promote a widescreen image and highquality sound. The picture is shot on either 65 mm or 35 mm negative film and the final print is released on 70 mm print film. The only difference between 65 mm and 70 mm film is the added width of 2.5 mm outside the perforation area on each edge of 70 mm film for the magnetic stripes. By the mid1980's, considerable interest had developed in digital sound on motion picture film. This interest was spurred to no small degree by the availability to the consumer of compact audio discs. This digital recording medium is quickly supplanting tape and longplay phonograph records for home sound systems because of its virtually flawless audio quality. 1990's and Beyond In 1990, Cinema Digital Sound (CDS) for film became a reality. The Cinema Digital Sound System was codeveloped by Optical Radiation Corporation and the Motion Picture and Television Products Division of Eastman Kodak Company. CDS features six discrete channels of pure digital sound optically encoded on the print film. CDS debuted in 1990 at selected theaters featuring Dick Tracy in the 70 mm format in New York City and Los Angeles. CDS provides filmmakers with a precise ability to control the direction and movement of sound to create a more compelling illusion of reality. Five discrete channels reproduce the full tonal and frequency ranges the human ear is capable of hearing. A separate subwoofer channel reproduces the lowest bass tones. CDS is designed to provide consistent audio quality for the life of the print. Wear and tear can reduce the audio quality of conventional 35 mm optical and 70 mm magnetic sound tracks. To provide this durability of the digital sound track, CDS features a sophisticated error correction system to ensure that every audience will hear opening night sound quality, even months later.
88
SUB WOOFER
SPEAKER
CENTER SPEAKER
• SPEAKER
SCREEN
Surround sound reaches its full potential when combined with CINEMA DIGITAL SOUND
Figure S3 The separation of sound into six discrete channels ensures that audiences will not only hear all of the subtleties of dialogue, effects, and music, the way it is meant to be heard, but from the special location where it originated.
The ability to encode digital sound optically on film required a major technological breakthrough providing the key to affordability and reliability of CDS. Theaters equipped with single channel surround speakers can easily retrofit for the dual channel surround of CDS. All it requires is installation of a digital decoder on the projector and a digitaltoanalog processor in the projection booth equipmentrack. Some theaters may consider the option to upgrade speaker systems to realize the full potential that CDS offers. CDS technology for 70 mm and 35 mm release prints is virtually the same. A decision was made to debut CDS in 70 mm format so the new audio system could be introduced in road show theaters. Motion pictures can be released in CDS format by simply remixing the audio made for conventional prints to six discrete channels of digital optical sound. Eventually recording and mixing techniques will evolve to take full advantage of CDS features. More original sound will be recorded and mixed digitally now that there is a way to release movies in digital sound format. 89
Magnetic and Photographic Sound Sound is recorded on a motion picture print in one of two ways, either magnetically on a metallic oxide strip coated on the film or photographically by an optically modulated light system. A magnetic sound track consists of a strip of metallic oxide coated along the edge of a motion picture film. Sound is recorded on this stripe by running it past a magnetic recording head that selectively magnetizes the metallic particles in the coating. Since coating formulations have been developed that are not affected by the processing chemicals, they can be applied to the film before (prestripe) or after (poststripe) processing. Seventymillimeter and some 35 mm prints may have multiple stripes for stereophonic sound and special sound effects. A second, much narrower stripe of the same thickness and, usually the same material is coated near the edge of the film support that is used for the sound stripe (between the perforations and the nearest edge) on 16 mm and super 8. This stripe is normally not used for magnetic recording; it balances the film mechanically to keep it from telescoping or binding against the reel flanges during projection and rewinding. A photographic sound track is a record of sound (voice, music, etc.) printed near the edge of a motion picture film. Photographic sound tracks are usually printed on the film at the same time as the photographic image. Thus, the two can also be duplicated simultaneously, unlike magnetic sound tracks which must be recorded on each print in a separate nonphotographic operation. A film producer who wants photographic sound sends the roughedited workprint, the original film, the script, and the final magnetic recording to a laboratory where conforming, editing, and addition of the sound track are accomplished. The original film, or a printing master with photographic sound track, is then printed for release. Photographic sound prints can be made from original films with magnetic sound stripes or from original films and separate magnetic tracks. A photographic sound track will last the life of the film and cannot be easily damaged through cleaning or other maintenance of the film. There is also no danger of accidentally erasing the track. However, the reproduction fidelity of photographic sound tracks can be degraded by dust particles and scratches. Also, changes cannot be made in a photographic sound track after it has been printed on the film. Magnetic tracks, on the other hand, are less susceptible to dust and dirt distortion and are degraded very little by scratches. The magnetic stripe offers other advantages. The additional height of the magnetic stripe raises the emulsion (image) off the base side of the next convolution of film on a reel, protecting the picture area from frictional damage, emulsiontobase sticking, etc. The stripe may also have higher fidelity sound (greater frequency response and better signaltonoise ratio). Photographic Tracks A photographic soundtrack negative consists of an exposed area whose width and area vary with the volume and frequency of sound recorded. The track looks like one or more narrow, jagged, blackandwhite patterns along 90
the edge of the film. For optimum quality on a variablearea sound track, the clear portions should be as transparent as possible, and the dark portions should have a density at wavelengths from 800 to 1000 mm between 1.0 and 1.8. Consequently, emulsions and processes that produce high contrast are generally used to record variablearea soundtrack negatives. Basics of Photographic Sound The reproduction of sound requires that the sound waves be converted into electrical signals which are then recorded. The record can then be played back, generating electrical signals, which can be converted back to sound waves by the speakers. In photographic sound reproduction, the actual sound record on the print is a silver, dye, or dyeplussilver image along the edge of the film. Figures 54A, B, and C show the components which convert the photographic sound track into electrical sound signals. The light energy from the lamp is formed into a narrow beam by a lens and aperture. The beam is transmitted through the soundtrack area of the film and then strikes a photocell.
Schematic of optical sound reproduction. Figure 54A
A sound track as seen through the aperture.
Figure 55
Bilateral Sound Track. Light attenuation by a sound track.
Figure 54B Dual Bilateral Sound Track.
Figure 56
Response of a photocell.
Figure 54C
91
As the film moves, the sound track itself varies, or modulates, the amount of light that reaches the photocell from the sound lamp. The photocell then converts the light energy into electrical energy. The electrical current produced by the photocell is directly proportional to the intensity of the light that reaches it. Photocells are made out of various photosensitive materials, each having a different spectral sensitivity. Virtually all 16 mm and 35 mm projectors have Sl or silicontype photocells, sensitive primarily in the infrared area. infrared radiation, which silver and to a lesser extent, silver sulfide are capable of doing. A sound track made of dye alone will not modulate the infrared radiation as effectively, reducing the signaltonoise ratio significantly. As the film moves past the sound aperture, the variation in the width of the track determines the amplitude of the signal generated, and the speed of the variation determines the frequency of the signal. There are several types of variablearea recordings. A unilateral track consists of modulations that are generated perpendicularly to the longitudinal dividing edge between the opaque and clear portions of the track. A bilateral track, Figure 56, uses modulations that are symmetrical about the longitudinal center line of the track. A dual bilateral track, Figure 56, has two bilateral images laid side by side; a multilateral track employs several bilateral images. The dual bilateral track is the most widely used because it minimizes distortion or signal loss resulting from any uneven illumination of the optical slit at the reproduction heads. Photographic SoundTrack Reproduction The effectiveness with which a photographic sound track is reproduced is a function of the spectral energy distribution of the illuminant, the spectral absorption of the soundtrack image, and the spectral response of the photoreceptor. The illuminant is usually a tungsten lamp having a comparatively low color temperature that provides relatively more energy in the red and infrared regions of the spectrum. Due to the multilayer construction of most color films, the color of the light that exposes the soundtrack image influences the trace characteristics and, therefore, is generally specified for the particular film concerned. Silver and silverplusdye soundtrack images are normally suitable for use with any projector and are printed from a negative sound track. Silver sulfide soundtrack images have somewhat lower quality. They are produced on reversal color films only and are themselves reversal images that are printed from a positive soundtrack original.
92
PROJECTION The success or failure of any finished film lies in the viewing. Once a print is made, the final responsibility for the quality of the screen image rests with the projection equipment and the people who handle the print This section covers the steps in inspecting a newly received print for flaws, the most common causes of film damage and abrasion, techniques for lubricating new prints, and techniques for cleaning film.
Handling and Inspection of MotionPicture Prints It is important to establish that the print meets your standards. When you receive a print, inspect it, following the recommendations below: • Maintain constant tension while rewinding to provide a smooth, tight reel. • Hold the film by the edges and wear clean, lintfree gloves while inspecting for damage or bad splices. • Remake faulty splices correctly, whether cement or tape. • Insist on a replacement reel if major cuts and damage are noted during your inspection. • Provide some means to maintain adequate relative humidity (60 percent is ideal) to help eliminate static electricity buildup in film transport systems. Common Causes of Abrasion and Wear To promote long life for your print, you should be alert to the causes of damage that can occur during projection. The five most common causes are discussed below: Excessive Tension. Too much tension in the film projection transport system usually results in objectionable projection noise and in perforation damage. If the film was properly lubricated at the laboratory, the source of the tension can be in the gate or at the feed and holdback sprockets. • Check for deposits on the trap rails and check the gate tension. Adjust gate tension just tight enough to provide a steady screen image. • Adjust tension on the projector reel spindles, if possible, to prevent singing sprockets. • If all of these points check out satisfactorily, check the 35 mm prints for proper lubrication of the edges on the emulsion side. The first step is to vary the gate tension over the entire range. If no improvement is obtained, inadequate edge lubrication should be suspected. Sixteenmillimeter films should have an overall lubricant. The coefficient of friction of the emulsion side of the unsatisfactory film should be compared to a satisfactory film by the test described in ANSI PHI.47 Methods for Detecting the Degree of Lubrication on Processed Photographic Film by the Paper Clip Friction Test. A coefficient of 0.2 or lower usually indicates a satisfactory level of lubrication.
93
Misalignment of Film in the Projector. This problem can cause damage at the corners of the perforations and lead to splitting and breaking at the perforation edge. • Check alignment of the film as it enters the feed sprocket or leaves the holdback sprocket • Check alignment of film in the projector gate. • Examine the print for damaged perforations before using it. (Order a new reel or print, if necessary.) Creased Edges. Film edges can become creased if: • the projector is improperly threaded so that the pad roller creases the film over the sprocket. • the film is under high tension and binds against some component or one of the roller flanges. RunOffs and Roping. This type of damage, often reported as sprocket marked, is caused when the film partially leaves the sprocket and rides over the sprocket teeth while under tension. • Check for misaligned splices and remake them. • Check for foldover damaged film sections; repair or replace the section (or reel), if necessary. • Check to see if any unperforated tape covers perforations and make necessary repairs. • Check the projector for proper threading and adjustment. Abrasions and Dirt. Primarily caused by careless handling, improper threading, and poorly maintained equipment; this kind of film damage is readily seen by the viewer. If you can answer yes to the following questions, you are well on your way to minimizing the problems of dirt and abrasion. • Is the projection area clean? Especially the floor and rewind bench? • Is the film riding correctly between roller flanges? • Is the print free of oil and grimy dirt? • Are smoking and eating (notorious dirt sources) prohibited in film handling areas? • Is there enough tension during rewinding so that the film does not slip on itself during fast starts and stops? (Much abrasion damage is caused by film slippage.) • Do you use clean, lintfree gloves and hold the film correctly during rewinding and inspection? • Do you avoid tightening a loose reel by pulling the film end until it snugs up? (This is another cause of abrasion damage.)
94
Cleaning MotionPicture Prints Clean and lubricate prints by drawing them between soft lintless cloths moistened with a preparation such as KODAK Movie Film Cleaner (with Lubricant). If a film is unsteady and noisy during the first projection, it may not have been lubricated at the processing laboratory. In this case, the film should be lubricated, not only to reduce noise but also to minimize film damage. Cleaning cloths of the following types are usually satisfactory: a good grade of Canton flannel, a short or mediumpile rayon or nylon plush, or a soft cotton batiste. These should be white, undyed, and free of fabric fillers and additives for stiffening. If in doubt, the cloths should be laundered before use. Place the film to be cleaned is placed on a rewind and thread the ladder stripe onto a takeup reel. As you rewind the film, draw it between two cloths moistened with the cleaner and lubricant. Constant light pressure provides continual contact between the film surface and the cloth. Do this slowly enough to permit the cleaner to evaporate completely before the film reaches the takeup reel. Frequent moistening of the cloths is recommended because the solvent evaporates rapidly.* To avoid scratching the film with accumulated dirt particles, refold the cloths often so that only clean areas will be in contact with the film. If streaks are noticed on the film after lubrication, you can remove them by buffing with a soft cloth before projection. Cleaning and lubrication should be accomplished with continuous, smooth rewinding of the whole reel. When you must stop to refold the cloth and apply more cleaner, back up the film about 1 foot (30.5 cm) before resuming the cleaning operation.
* KODAK Movie Film Cleaner (with Lubricant) does not contain carbon tctrachloride. Even so, you should use the cleaner with adequate ventilation. Forcedair ventilation should be provided. No matter what type of cleaner you are using, follow the instructions on the container.
95
DEALING WITH A MOTIONPICTURE LABORATORY During post production, you will be spending quite a bit of time and money with a film laboratory. Locating the right lab is extremely important. Ideally, you should have some feeling for a lead early in the production phase, before you have many hours worth of exposed film on your hands and are wondering what to do with it. How do you find that lab? The purpose of this section is to explain how laboratory operations fit into your total production. First'come some tips on selecting a lab. Next is a walkthrough of laboratory operations during a typical production. The next section deals with processing and printing operations and equipment so that you can appreciate what can be done with your film once you've exposed it.
Tips on Selecting a Laboratory Generally, the laboratory that gets your business will be the one whose capabilities best match the requirements for your particular job. Laboratories differ in terms of the technical services they offer, personnel, track record on similar projects, size and location, prices, and so on. Weight all of these factors in selecting the right laboratory for the job at hand. Every production has different requirements. The laboratory selected to do a production filmed in 35 mm for television distribution will probably be different from the one chosen to handle a job shot in 16 mm for reduction to super 8 to be used in pointofpurchase advertising. The challenge is to find the lab that can satisfy the greatest number of your needs on schedule and within budget. There are a number of tradeoffs. Consider the question of size. The big lab can usually offer lower prices due to their largevolume operation, more complete inhouse services, and excellent quality control. The small laboratory usually offers custom handling and easy access to the right people for advice and counsel. But they may have to charge more to support their custom operation or subcontract more of the job. Consider the location. If a laboratory is a significant distance from your place of business, you will be faced with the potential hazards and increased costs of shipping valuable footage to and from the lab. Daily communications with the lab may also be more difficult. Consider your confidence in the laboratory. The selected laboratory should be looked upon as a silent partner in the production of a motion picture. The laboratory should be taken into the producer's confidence, kept informed about the films and photographic techniques being used, advised of the specific objectives, and alerted to any problems that might develop. Given this relationship, the laboratory can assist and simplify your endeavors. You should select a laboratory you feel takes your interests seriously. These important steps in your production can be smoothed considerably if adequate communications are established right from the start. Both you and your laboratory should know what is expectedand when to expect it. 96
• Know your needs. Have a good idea of what you want from a laboratory and then talk about those needs with several laboratories before you make a choice. In your discussions, be sure to relay your ideas about such things as editing, dubbing, special effects, animation, etc, so the lab can help you accomplish these tasks in the best way possible. • Get acquainted. Once you have made your choice of laboratories, get to know, as well as possible, the people who will do your work. Tell them as much as you can about yourself, your needs, and your style. The more you communicate with them about yourself and your production, the better they can serve you. • Get it in writing. Facetoface discussions and telephone calls are necessary for efficient work flow; but when it comes to specifying what you want, when you want it, and how much it will cost, a carefully written documentthe purchase orderis a must. Listed below are some of the principal services offered by commercial motion picture laboratories. Few laboratories will offer all the services listed but most of them will provide a major portion. • Processing camera film. (Special overnight pickup and delivery, or weekend service is available in some places by prearrangement.) Find out what processes are available, including special techniques (e.g. flashing or force processing). • Furnishing advice to help with technical or even aesthetic problems. • Printing and duplicating from camera films for workprints or releaseprints. Most laboratories will print or duplicate the camera film after it is processed. They may also hold the original in their vault and forward the print for use as a workprint. Thus the original is protected from damage in handling until it is needed for final conforming. • Blackandwhite printing from a color original to produce a workprint for sound editing. • Edge numbering of originals and workprints to facilitate editing. • Editing, cutting, splicing, and assembling as directed by the producer. • Conforming by matching the original camera film to the workprint as edited by the producer. • Optical effects which these include dissolves, wipes, fades, freeze frames, etc.
97
Laboratory Services: A WalkThrough To help you visualize the way a laboratory's operations interact with you and your production, this walkthrough gives you three views of scheduling. First is a flowchart of operations from preproduction through various laboratory operations to delivery of the edited, printed film. The chart shows a graphic description of the close communication between lab and cinematographer that produces a satisfactory final print. Next is a narrative about the production of a film for television that demonstrates the behind the scenes laboratory work that keeps a production on schedule. Last is a day today schedule, from shooting to release print, of this production.
Services and Work Flow Through the Film Laboratory
Now, let's describe our show. This weekly onehour series is produced by a major studio that has a network contract requiring the production of 24 episodes. The show routinely includes practical location photography (day and night). Six to seven days of filming are common for each show. Here's how the laboratory fits into the production. On most days, the production company's exposed 35 mm negative is at the studio's camera department by 7:00 p.m. A truck from the laboratory picks up the negative 98
along with those of several other production. Often, the truck makes several trips throughout the evening. The first batch of negatives arrives by lab truck, is sorted by the directions on the film cans (flashing, forcing, priorities, etc.), and prepared
The roll is ultrasonically cleaned and printed at exposure values that had been derived through a "finetuning" of timing information obtained early in the production season on the laboratory's electronic color analyzer. The daily print is developed and screened by the laboratory customer representative usually between 6:00 and 9:00 a.m. The print is projected full aperture at approximately 120 ft/min (32 frames per second) so any film, camera, or laboratory problems can be seen. The daily prints are delivered to the production company's editors by 9:00 a.m. for syncing with the sound track that has been transferred from 1/4inch magnetic tape to 35 mm magnetic film. At 1:00 p.m. the director and other production personnel screen the synced dailies on doublesystem projectors. The laboratory won't be involved in this particular episode in the series for about two weeks (in some cases for two months, depending on the activities of the production company). During this time, the studio is editing, The laboratory's next job is to assemble these elements and generate the final composite prints for this episode. The network usually requires two 35 mm prints (for New York and Los Angeles) and three to fifteen 16 mm prints. Two of the 16 mm prints are backup prints for the 35's, one is for Canadian television (which usually is broadcast 3 to 4 days before the U.S. air date), and the remainder are split regionally within the network system. This phase begins with close communications between the production company's negative cutter and the laboratory. As reels near completion, the negative cutter delivers the cut negative with instructions to the lab. The reel may be only 90 percent complete, but the lab can begin to splice and notch the negative, leaving leader in the areas that are not firm or are awaiting inclusion of laboratorycreated segments (dissolves, fades, and titles) primarily on color reversal intermediate (CRI) or color intermediate film stock. The optical effects elements are usually created by an independent optical house rather than the laboratory. When the negative has been spliced and notched, it is timed on an electronic analyzer to determine the exposure values to be used in the printer. The timing information is used on a proof printer which prints only a few frames of each scene. This proof print is screened (singleframe projection) to identify any further color or density corrections required. A complete composite print (answer print) is then made and evaluated on the analyzer. Once the answer print has been accepted by the producer, a second 35 mm print is made. A 16 mm wetgate reduction CRI is made, using the final timing derived for the 35 mm answer print. From this 16 mm reduction, the required 16 mm prints are contact printed. On the fourth day after the laboratory received the cut negative, the answer print is screened at the laboratory for representatives of the production company and the network, and the print is approved. 99
Daytoday Schedule of the Production Event
Duration
Reproduction
16 w eeks. Depends on how many locations to be scouted and/or how many sets to be constructed.
Days 06
Production
Photography—6 days.
Day 2
Postproduction
28 weeks. Laboratory operations begin during shooting and include processing the negative, daily workprint printing, cutting the workprint into sequences, making optical effects, adding stock footage and sound effects, making titles, and dubbing (voice, sound effects, and music). Optical effects are scheduled whenever the individual scene elements are available. Several labs may be involved in some phase of these operations.
Day 12
1. First Cut
Includes action and voice only, in rough sequences. No opticals, titles, sound effects, although some opticals and titles are being made.
Day 24
2. Final Cut
Workprint. More precisely edited into final form. Some opticals but no titles or sound effects.
Starting on Day
100
Daytoday Schedule of the Production Starting on Day
Event
Duration
Days 2531
3. Negative Cut
Music composed and scored, sound e ffects made, opticals finished. Camera negative physically cut to conform to final cut of the workprint. Dupe negatives spliced in where there are opticals and title negative footage added. Actual splicing is done at the laboratory.
Day 32
4. Dubbing
13 days. All sound materials (live music, recorded music, voice, sound effects such as gunshots, footsteps, etc) combined into a composite magnetic sound track. Magnetic track transferred to optical track.
Days 34, 35, & 36
5. First Trial
Film shows aesthetic defects in some areas. Needs tightening up and polishing, s light r ecutting. in titles
Day 37
6. First Answer Print 35 mm
Contains everything; becomes New York air print.
Day 38
Second Answer Print
Slight color corrections; becomes Los Angeles air print.
Day 39
7. 16 mm Prints
Reduction CRI and ten 16 mm prints.
101
MOTIONPICTURE LABORATORY OPERATIONS One important consideration when selecting film—one too often overlooked—is the processing requirements for a given film and the printing needs for the whole production. One way to better appreciate the sophisticated technology that turns your exposed camera film into good projection film is to understand the processes and equipment in the modern film laboratory. In this section, we will describe the operations and equipment involved in processing and printing your film.
Processing Equipment The modern motionpicture laboratory uses the continuous processor, a machine that provides the most efficient way of handling long lengths of film. Other kinds of equipment can be built or purchased for development of small amounts of blackandwhite footage, but the continuous processor meets the quantity and quality demands of professional processing. In essence, the continuous processor moves film through the appropriate sequences of developers, fixers (or stop baths), washes, and dryer at a carefully controlled speed. The processor also controls solution temperature and agitation to produce optimum results for the particular kind of film being processed.
Construction of Containers Glass, hard rubber, polyethylene, 316 stainless steel, and titanium are the materials most commonly used in the construction of containers for mixing, storing, and using photographic solutions. Not all metals are suitable. Tin, copper, and their alloys may cause serious chemical fog or rapid oxidation when used with developers. Do not use aluminum, zinc, or galvanized iron with either developers or fixing baths.
Transport Design The film follows a helical path by moving on partially or totally submerged banks of rollers through the various solutions (Figure 57). Squeegees (Figure 58) or wipers located between the different tanks remove most of the liquid from the film surface. The most common method of moving film through a processor is by friction between the rotating spools and the base side of the film. The other major method is by sprockets incorporated on the spools which engage the film perforations.
102
Spring This type of wiperblade squeegee assembly is used on many processors.
Figure 58
Roller undercut in image area.
Helical path of film through a single rack and tank assembly
Figure 57
Roller with softtouch tire installed.
Figure 59
The film path through the processor wet sections permits only the base side of the film to contact the rollers. In this way, the emulsion is protected from possible physical damage that might occur if the soft, wet emulsion came in contact with the plastic spool surfaces. However, in the dry sections (feedon and takeoff) of some processing machines, there may be emulsion ridges that touch only edges of the film, or the rollers can be flat and covered with softtouch tires for uniform film support across the roller width and to prevent scratching of the support in the image area. See Figure 59.
Access Time Two of the most widely discussed and perhaps the most misunderstood items relating to any processor are speed and access time. Speed refers to the time required for a specific point on a film to travel a specific distance and is measured in feet or meres per minute. Access time refers to the time it takes a particular length of film to be completely processed. Regardless of machine transport speed, which can range from 15 to hundreds of feet per
103
minute, film cannot be processed faster than the total of the times required in
seconds plus 1 minute to complete the process. With a 150foot roll, access time will be 14 minutes 15 seconds plus 10 minutes.
Time and Temperature In blackandwhite processing, time and temperature may vary widely among motion picture laboratories. Each laboratory selects the appropriate development times and temperatures for the films being processed in a particular machine and with a particular formula. This is accomplished by producing a timegamma curve, as discussed on page 24. (Some modifications in the controlgamma aim may be necessary depending upon the type of sensitometer or densitometer being used.) For color films, specified temperature tolerances, particularly those for the developers, are critical. Developer tolerances of ±0.3°C (±0.5°F) are typical. Appreciable deviation from these limits results in speed and color balance changes. Many commercial motion picture laboratories have found it feasible and profitable, in terms of consistent quality, to control the developer temperature to within ±0.15°C (±0.25°F), or even less. Process ECN2 requires that the developer temperature be held within ±0.1 °C (±0.2°F). Controlling processing time is also more critical with color films than with blackandwhite films because any changes that occur in color emulsions may not be equal in all layers. Improper color reproduction can result from speed shifts, contrast changes, increased fog, etc., in any of the layers. Therefore, a good lab adheres closely to the exact processing specifications for the particular equipment and materials.
Agitation If exposed photographic materials are placed in a developer and allowed to develop without movement, the action slows down because the developing chemicals in contact with the film surface become exhausted. If the film or the solution is agitated, however, fresh solution is continually brought to the emulsion surface, and the development continues. An equally important effect of agitation is prevention of uneven development that may result in mottle, a nonuniform density in the print that makes it look blotchy. If there is no agitation, the exhausted solution, loaded with development by products, may flow slowly across the emulsion from dense areas to less dense areas and produce uneven streaks. Agitation keeps the solution uniform throughout and avoids uneven development. In color processing, proper agitation is especially critical during the initial development step. The recommended agitation techniques will vary, depending upon the process and equipment being used. The film movement, as it passes through the developer solution is not always sufficient to create adequate agitation. 104
Mechanical Specifications If film is to be processed satisfactorily as it moves through the machine, it must be immersed in solutions of the correct temperature for the proper length of time. In addition, processing solutions must be adequately replenished and filtered, and sufficiently agitated. These requirements are commonly called the mechanical specifications. The only valid processing change—made for the purpose of force processing (for more camera speed under lowlight conditions)—involves increasing the developer (camera negative) or first developer (reversal camera film) time and/or temperature. The time that film is immersed in a particular solution depends upon the length of the film path in each tank and the machine speed. Generally, time is fixed by the number of rollers per rack and the number of racks threaded in a tank. Usually, individual rack times can be changed by rethreading the rack or using a rack equipped with an adjustable lowershaft assembly. Temperatures on most processors are controlled automatically, often to with in +0.1C but can usually be adjusted manually to accommodate any desired temperature changes. The laboratory also keeps a highly accurate thermometer available to double check the processor temperature gauges.
Process Control The degree of development in a negativepositive process or first development in a reversal process is the most important factor in determining the final image quality. Careful control is critical at this point Development is affected by the temperatures and chemical composition of the developer (or first developer), the time of contact between the film and the solution, and the degree of agitation. The other processing steps are also affected by the same factors. When all is well with the process, the output from the continuous objective measurement. Sensitometric control strip density values, when plotted in graphic form, give an operator that objective information about the condition of the process. These measurements are made before, during, and after a processing run for maximum control of quality.
105
The operator also checks the physical operation of the machine periodically to ensure good results. A good lab observes the following practices in the physical control of a process: • Use of correct processing temperatures, which are checked often. Thermometers and temperaturecontrolling devices are calibrated periodically to insure that the instruments are operating properly. The temperatures of all solutions are kept within specification to minimize dimensional changes in the emulsion. • Use of recommended processing times. Machine speed is checked by carefully measuring the time it takes for a given length of film to pass a specific point. Knowing it is possible to use an incorrect processing time when a machine uses different threadups for different film stocks, the careful laboratory checks the solution times every time there is a threading change. Consider that, for blackandwhite negative or positive process, one might run up to seven films having nine possible development times through Developer D96 in the course of a few hours. • Use of the recommended replenishment rates. Accurate replenishment increases the useful life of solutions to a great extent by replacing ingredients that are depleted and maintains the process at a constant, efficient level. To prevent serious outofcontrol situations and chemical waste, laboratories routinely check the accuracy of their replenisher delivery systems. • An accurate daily record is kept of conditions affecting the process, including developer temperature, amount of film processed, volume of replenisher added, and identification numbers of control strips processed at particular times.
106
MARKETING A FILM
"People don't buy goods and services; they buy solutions to problems. People are accustomed to learning through film." • Filmmakers who learn how to market and how to communicate with clients are the ones who make films. • You have nothing to sell, of course, except yourself—and the promise that you can deliver a film that meets your client's needs. • Don't try for a film that will win prizes. If you try for a film that will best serve your client's needs, you will find yourself with a prizewinner...and a recommendation for another job. • Your reputation is as good as your last film. You build a reputation by taking care of business every day as though your reputation were at stake, because it is.
Film as a Business Tool "Corporations are closer to the film medium, because they make commercials and they're more exposed to film; the educational foundations are not the best source of funds for films." Knowing how to make a film—knowing how to use the medium to communicate a message—is not enough if you are to become successful. You must also know how to communicate with people who need the films so that you can get a chance to use your creative talents. In business, that's known as marketing. Your marketing should begin with a sensible look at what you have to offer. In reality, film is not what you have to offer. What you have to offer are solutions to problems, using film as the medium for communication. That's what nontheatrical filmmaking is all about. There are several areas open to the nontheatrical filmmaker—business, All have a use for sponsored nontheatrical films—films that teach, films that promote, films that pass along information. Basically, there are three types of communication problems: Those related to skill and knowledge, motivational problems, and problems of information; and, of course, some communication problems are a combination of the three. Problems in the skillknowledge area usually involve situations where someone lacks the understanding necessary to perform a job. People have to be trained to make products. People have to be instructed in safety procedures. People have to be coached in selling the product The idea is this: People who know more are more effective. That's a good investment 107
In the motivational area, the problem is that someone may not want to do a job. Most recognize that people who want to work are more productive and will work harder toward a solution to the problem. Motivational problems can also involve prospective clients. The solution in this case can usually be found in the area of more effective advertising and sales promotion. In the informational area, the problem is what most people would refer to as public relations. Corporate and product visibility is very important to most companies, since exposure and goodwill help sell products. A company that perceives a need for solving informational problems will invest in a solution that best reaches its audience. The point is, business spends money to make money. A smart business person will provide the money to make a film once there is an understanding that film will help solve a problem. Your job is to discover where a film will help.
Potential Clients "Organizations (business corporations, universities, churches, hospitals) have internal communications problems, such as training their employees, communicating government regulations and rules, motivating people, and creating a sense of community among their people so they work as teams; those are common problems for any kind of organization." Every company is a potential client. First, start with a list of companies in your area. Use the phone book, a Chamber of Commerce listing, or the Fortune 500, trade listings. Some companies, because of size, will be obvious prospects. Of course, if those companies use film, they probably have many other filmmakers calling on them already. But you have nothing to lose by offering your services as well. It's true that you may not have anything to offer that they are not getting now, but you'll never know unless you contact them. "Trade journals will tell you what's going on and what kinds of films are being made and who's making them. Also, industries will address business problems in their annual reports...Read the business page in your newspaper; look to see where trends are happening." There may be several people to contact in each company. Internal structures are easy enough to penetrate if you keep the communication needs in mind. One way to get started is to call the switchboard or drop by the lobby, and ask questions: "Could I speak to the manager of the Training Department?" "Who is in charge of Sales Promotion?" "I'd like to talk to someone in Corporate Relations." ...and so on. It may 108
take a while, but most people are helpful once they understand that you are trying to find someone you can show your talents to. Within each company there may be several different departments that have a need for film. You will find that department names vary greatly—AV Services, Advertising and Sales Promotion, Media Services, Marketing Development—but their purposes are all the same: to solve communication problems. Somewhere in these departments you will find one or more prospects. They may deal directly with you; on the other hand, they may be required to request the work through a central medial department. Don't forget, a company with one prospect for you probably has two. "To reach individuals in a company, you have to first work through the 'corporate tree' and pick the branch that you feel needs a film." A second way to get potential clients is to offer them a solution to a problem you perceive before you ever meet. This involves a good deal of homework. Look in trade journals, annual reports, and business papers and magazines. Each will give you an idea of current business problems. It may spark an idea that you can develop into a proposal. Once your ideas are thought out, place a few phone calls to the company until you find someone who is willing to briefly discuss you idea. If that person seems interested, you can send the full proposal for further investigation. If the company is not interested in that particular proposal, you will have shown yourself to be someone interested in solving its problems, and that alone may help you get some work. And don't forget that your prospects may be working with cyclical budgets. For example, the textile industry will probably be most busy twice a year and will have to introduce new products—in the spring and fall. Car manufacturers come out with their new products in the spring and fall. Summer recreation has an obvious selling period, as does winter recreation. Budgets for producing work becomes available before those selling periods. So, your marketing efforts have to coincide with the budgets, not with the selling periods. Direct your efforts toward the future; if your prospect doesn't save money now, the money will come eventually. "What you have to get a little more aware of, and perhaps a heck of a lot more of, is corporate budgeting. Corporate budgets have certain approval cycles, certain processes, and there are times that you can get at the money and times that you can't. You don't want to do all your homework and then go in there and find that there's no water in the well." Before you ever reach a potential client's desk, you have to decide why you are going to meet with that person. Certainly you want to introduce yourself and, if possible, show some samples of your work. But you should be trying to do more than that so that you can best define what you have to 109
offer. Among other things, you will want to find out what communications needs exist in the company, how these needs are currently solved, and whether the person you are talking to has the power or influence to hire you. When you meet someone for the first time, you have the opportunity to begin a lasting business relationship. You know what you can do. Now is your chance to find out what you can do for your prospect. You can only do that by determining what your prospect needs.
Client's Communication Requirements "You have to find out first of all how they think, how they operate, what their business is like, and how they make decisions." There are two ways to approach a communication problem. One way is to let the client take control; you do that by talking about yourself, your attitudes, your previous successes with other similar problems. This approach is not particularly successful. A more effective way is to take control yourself—define your meeting; you're there to get business. You can help yourself by paying attention to the problem. Listen to what the client has to say and ask questions that will reveal why your client thinks of the problem as unique. But it's not enough for you to discover your client's needs. You also have to help the client's needs. You also have to help the client really understand the needs and reach agreement on them. Only when you have reached that point can you begin to talk about solutions. You may have to hold several meetings before you begin to talk about film, which is just the medium for solving the problem. The importance of good communication skills in determining your client's needs cannot be overestimated Remember, you are in marketing as well as filmmaking. Marketing requires certain skills that you may never have considered. Keep in mind that your job is to solve your client's problem. You may understand the problem one way; your client may understand the problem differently. You must learn to listen carefully and question your client skillfully so that you can both agree on a definite solution to the problem. You may be able to create a great film; but if your client isn't happy, it may be your last film.
Reaching Agreement on Need for Film At the end of your first meeting with a prospect, some action has to be taken if you are going to continue to work with the prospect and perhaps do a film. This, again, is continuing your control. In business, this point in the action is called a close. What it means is that you must get your prospect to agree to do something. You may have to suggest what to do next. It may be to write a proposal, meet with other people, or continue discussing how you might help the company. You have to do something or the prospect is lost to you. 110
If you continue to work with the prospect, you will find that at every point along the way there are places where action must definitely be taken. For example, when you have submitted a proposal which in many cases is simply to ask: "Shall we go ahead with it then" or "Does it meet with your approval?" When you ask for a positive action and the prospect says No, don't give up, not yet. First, take the time to find out why your prospect has said no. It may be that the proposal you have submitted doesn't clearly solve the problem. In that case, your job is easy; just write another proposal. Perhaps the client isn't convinced that you can do the job. In that case, you can ask the client if references from other people would be helpful. Whatever you do, don't let the word no stop you until you find out why. And when you find out why, closethat is, take an action that will get you a yes. At some point in the filmmaking processbefore you begin productionyou will have to communicate with people who hold the purse stringsyou will have to get the proposal approved. Even though your client may understand the creative and technical aspects of filmmaking as well as you do, somewhere along the line you will have to talk to people who relate to costs differently than you. Keep in mind that your client's company doesn't need a film per see, it needs solutions to problems. The film you create will have to solve those problems in costeffective ways. It goes back to the three kinds of communication needs. Ask yourself a few questions: Will the company be able to sell more products? Will it be able to train people better? Will it now be able to communicate information to more people more effectively? Will the employees be sufficiently motivated by the film to justify the cost of producing it? All of these questions are related in one way or another to profit. If the company can sell more goods and services, get more work done, disseminate more necessary information using audiovisuals, and if it can get more in return than it spends on your film, then that is a gain for the company and the kind of "bottom line" that interests those who have final approval of the project.
them to help solve their internal or external communication problems." To summarize, finding and keeping clients is a sequential marketing process. Even though you are only marketing yourself, there is a logical order of steps to go through in order to get down to business of making a film. Basically, it involves doing things one step at a time. First, you have to decide where the potential jobs are. Second, you have to find out whom to talk to. Before you ever see that person, you have to do some homework in two areas. Find out as much as you can about your prospect's organizational 111
setup and communication needs. Then, decide what it is you have to talk about so you can present yourself properly. When you see the prospect, you will go through a series of steps involving questioning and listening to find out the communication needs of And, if the prospect looks good, you have to close—which means that, if nothing else, you decide when to meet again to talk more specifically about certain projects or needs within the company. After you have a project or perhaps an order to get a project, you have to write a proposal based on the objectives that you and your client have worked out. You may even have to write a second proposal detailing the business advantages to the company as well as alternative proposals. And finally, you have to secure a contract before you begin production. At this point, your marketing job is not over. Even though you are now concentrating most of your efforts on making the film, you must still stay in close contact with your clients to keep them uptodate on the progress of the film and secure the necessary approvals along the way. Marketing a film is very much like producing a film; every step must be considered in order to meet the client's needs as the client sees them. Don't let the term frighten you...it's simply a matter of taking care of business. Filmmakers tend to think of themselves as artists, apart from the clutter of the business world. But no matter how alien the concept of marketing seems, it is still a skill that must be learned and developed. Why? Because marketing is a skill that will help you make the kind of films you want.
"Take that next step beyond y our f ilmmaking skills...business skills
next persondoing more than the client expects."
112
DISTRIBUTION AND PROMOTION • Your creative work is of little value unless you have an audience. • If you don't have a plan, it will stay in the can. • When you target your audience, you target your potential for payback, • There are as many outlets for good films as there are good films. A good film is one that is aimed at a particular audience. You must give the audience a chance to see it by making it visible with promotion, available with distribution, and usable with support materials and proper maintenance. The distribution and promotion phase is, many times, a matter of rote. Many companies have predetermined distribution channels, especially with materials created for internal use (training outlets or salespeople) or for well established clients (dealers or distributors). You may, however, be able to help your client choose the distribution format. Will the film be shot in 16 mm and converted to 35 mm, then converted back to 16 mm for television use? Will it be shot in 35 mm and converted to 16 mm for distribution? Will the same film have several uses in several formats? Your client's answers will help you determine both the original format and the distribution format, determine costs for the total needs of your client, and avoid serious mistakes when choosing production techniques. A high contrast blackandwhite film, for example, might be dramatic in a theater setting but look muddy or washed out on a television screen. Inadequate planning can ruin even your best work or cause unnecessary costs for your client, and for that reason the distribution format must be considered in your proposal. Many times, distribution and promotion are the critical points in the decision to makeor not makea film. Is there an audience for the film? How will you get it to them? How will they know the film is available? These questions must be addressed in the planning stages; and when the answers are not obvious, it is very good business to consult a professional distributor. Early involvement with a professional film distributor is essential in getting a generalinterest film production to its target audience. Whether you are aiming at a large, single audience or widely diversified audiences, a distribution service is an excellent vehicle for publicizing and communicating your film's message. This part covers general considerations for distribution planning, the potential distribution channels for reaching mass audiences, important film ingredients influencing distribution methods, and the many services offered by the distributor (including promotional pieces, print inventory, supporting materials, film maintenance).
113
General Market Considerations "We have just made a new film. Could you come over and take a look at it and give us some suggestions for distribution?" This type of request (which originates from film producers or from the sponsors of a producer's film) is too often heard by professional film distributors. The above question should be answered at the planning stage, not after the film is in the can. Early in the game, consider not only why the film, but also where the film. Unfortunately, film producers are often not wellequipped to communicate to their clients all of the effective distribution alternatives. If you feel at all uncomfortable with any of the distribution areas, get in touch with a film distributor who can answer your questions and handle your specific needs. Not all industrial films are suitable for mass distribution, nor are their target a mass audience. Films are often produced to sell a client's product, point of view, or service to an extremely narrow market (e. g., medical films, military films). These films are carefully aimed at the target audience and usually delivered directly by the sponsor or his or her sales personnel. Professional distribution is normally not required for this type of film. This part is really addressed to the films that are made for unclassified or general audiences. Nontheatrical films are generally directed to one or more of the five potential channels of distribution: • Educational • Specialinterest groups • Broadcast TV • Cable TV • Vacation resorts Schools and specialinterest groups account for the greatest utilization of sponsored films. Your films can also receive considerable visibility through the other four distribution channels. If you want to target your films at these areas most effectively, you should really contact a professional distributor. Educational There are four major subcategories in the educational field: grade school, junior high school, senior high school, and college. And, even within these, there are many other subcategories, such as: boys, girls, and coeds. Instructional films covering the following subject areas (among many others) are regularly shown to schoolage students: • Home Economics • Science • Physical Education • Health • Social Studies • Business and Economics • Vocational Guidance • Arts and Crafts 114
Also within this age range are various nonschool youth organizations such as: Boy Scouts, Girl Scouts, Little League, and other sports groups, YMCA, YWCA, etc. SpecialInterest The specialinterest grouping encompasses business and professional organizations, religious groups, civic and social clubs, etc. Listed below are many of the areas that make up this large and diverse category: • Business and Industry (e.g., oil companies, computer companies, electronics factories, automobile companies) • Service and Fraternal Organizations (Rotary, Kiwanis, Masons) • Church groups (Finance Committees, PastorParish Relations) • Sports groupshunting, fishing, automobile clubs (NASCAR, SCCA), ski clubs, hiking clubs • Federal Government agencies (Internal Revenue Service, Health, Education, and Welfare Department) • State agencies (Department of Motor Vehicles, Transportation Department) • Military branches (Army, Navy, Air Force, Marines) • Hospitals The above is not intended to limit the possibilities, but merely to point out the broad range of potential target audiences within the specialinterest category. Broadcast Television Broadcast television (commercial and educational) provides the quickest method of exposing many thousands of viewers to your film at one time and
13 1/2 or 27 1/2 minutes are most suitable for the average TV station, and less prevalent film lengths include 3 to 5 minutes and 7 to 10 minutes for use as fill material (fulllength film or sports event running less than a twohour programming slot). Generally, TV stations broadcast from 2 to 4 hours of sponsored films every week. Cable Television Cable television (CATV) is a steadily growing market. Similar to broadcast TV, CATV enables you to show your film to many of the cable viewers (a total of about 10 million homes in 7,000 communities) at a number of locations throughout the country. Again, your film should have wide audience appeal, be appropriate for many geographic areas, and run either 13 1/2,27 1/2, 3 to 5, or 7 to 10 minutes. Although your film may be meant for a certain specialinterest regional group, it could also be of interest to people in other communities.
115
Vacation Resorts Vacation resorts are another excellent area for promoting your films. You have the opportunity to reach many community adult groups that do not normally meet in the summertime. Movies are frequently offered for evening entertainment by the management for resort hotels, motels, camps, or other similar vacation habitats. This approach enables you to communicate with a wide range of relatively affluent viewers (with the appropriate type of filmskiing, fishing culture) in a leisurely and relaxed atmosphere.
Film Ingredients In addition to considering the categories of audiences and potential distribution channels, you should also examine some of the important parts of a successfully designed film: the running time, the advantages and disadvantages of using professional talent versus industrial talent, and the film content. Running Time The running time of your film will have a significant effect on the way it is distributed. Generally, educators are looking for appropriate films running from 15 to 30 minutes. In fact, many will avoid the use of extremely short films simply because the time required to obtain and set up a movie projector cannot be justified for a few minutes of screen time. Adult organizations, on the other hand, will normally shy away from film this long, preferring presentations that run less than 15 minutes. Therefore, you should carefully evaluate the length of your film based on the target audience. You might even want to produce two different lengths (different versions) of the film to maximize usage for both the adult and the school audiences. Professional Versus "Industrial" Talent One of your responsibilities is to decide whether to use recognized (name) talent or unrecognized talent. There are advantages to using either type of talent (cost considerations and film impact). The use of good industrial performers in place of name talent can result in an excellent film; for the most part, viewers are primarily concerned with the film's message. If you decide to go with recognized talent, consider these potential (yet remote) conditions. An actor involved in your production could possibly do a film for a competitive company and create credibility problems. Or, such a personality might not be available when needed, could be too expensive, lose popularity, pass away, or even date a film. On the other hand, there are certain films that require appropriate stars (films pertaining to major sports, such as skiing, bowling, auto racing, soccer, football, baseball).
116
Film Content Film content must be a blend of what the client deems important to get across to the public and the producer's interpretation of those aims. Some producers, unfortunately, make elaborate films strictly to win filmmaking awards and to gain recognition; the content and the cinematic techniques applied may be accentuated to that end. It is conceivable that the client's/sponsor's original purpose for the film has been somewhat misdirected. The real objective is to meet all of your client's expectations.
Distributor Services The actual elements of film distribution are simple in theory but vastly more complex in practice. You might think that to successfully market your film you need only an audience and a method of getting the film to the viewers. However, distribution is really a more complex science. Mass audiences, such as classroom students (kindergarten to college level), are fairly easy to locate. Other target audiences (skiers belonging to ski clubs and members of hunting and fishing Rod and Gun clubs)are not particularly hard to reach because they belong to wellknown organizations. However, certain desired target audiences are difficult to find and perhaps not as easily influenced toward using your film. This section, then, covers the advantages of using film distributors and the techniques they use to help you and your sponsor determine less obvious target audiences. Promotional Ideas Efficient promotion can heavily affect overall film distribution. To assist the sponsor, supplemental promo literature (ranging from a single handout to a series of brochures and catalogs) can be prepared by the distributor. Regardless of the format chosen and the cost of producing such a promotional unit, there will be an extra expense in getting materials to the audiences. Obviously, a directmail system will play a vital role in getting promotional media to the film users; to help you, distributors have the latest comprehensive mailing lists of nationwide business and educational institutions. The handling of promotional materials can range from selfmailers to elaborate catalogs. Costs for an outside vendor's services (layout and printing) are only part of the expenses that must be factored in; you may also be charged for mailing lists, handling, and postage. Selfpromotion by a sponsor who has a single film would cost more than any other unit listing several films for which promotional expenses could be amortized. The only time a distributor might charge the sponsor a special fee would be for a very unique promotion. If the sponsor's film is listed in general catalogs indicating numerous film availabilities, then there will not be a separate distributor's charge. Print Inventory Print inventory is virtually the key element in effective film distribution. The sponsor will need a sufficient number of prints on hand to adequately 117
supply all of the intended target audiences. Unfortunately, many films are produced without consideration given to this subject. Frequently only a minimal budget is set aside for film printing costs. Based on an old rule of thumb of approximately 20 different audience bookings per print per year, a sponsor can roughly calculate how many audiences can be reached in a year on varying print inventories and thus estimate the cost of such distribution including prints and commercial circulation. Again, be sure you account for anticipated distribution costs in your planning and budgeting activities. Check with several film distributors concerning pricing for printinventory services and factor those expenses into the distribution plan. It would be unfortunate for you to discover late in the game that sufficient dollars were not set aside for proper film distribution. Supporting Materials Besides considering print inventory and distribution cost, you should also many films are sent to audiences without adequate support information; by merely supplying a business leader's (or teacher's) booklet or guide with the film, you can make it a much more appealing and meaningful package from the audience's standpoint. Typical subjects include: a capsule description of the film, an indepth discussion of the film's historical context, and a precise presentation on the products involved (including prices). Other possible uses: hints on product features and usage, suggestions for discussion after the screening, demonstration kits for teachers, tidal charts for fishermen, game laws for hunters, or exercise suggestions for athletes. Film Maintenance Finally, most film distributors will offer a print maintenance program. Under such an agreement, your prints will be completely inspected for torn or open splices, torn sprockets or other imperfections, scratches, and missing footage. Early correction of these problems will protect your prints from possible damage and loss. The distributor will place protective, colored head and tail leaders (complete with the address of the distributor) on the release prints, because: • You can easily identify the film by title and print number. • Color coding of the leader will immediately indicate if the print is heads or tails out (to determine if rewinding is necessary). • The leader will indirectly guard against film loss through the mail, in the event that the film and its case become separated. • The leader will protect the film from damages occurring by way of improper projector threading. • The leader will clear the projector gate of dust and debris before the film is projected.
118
GLOSSARY OF MOTIONPICTURE TERMS A & B CUTTING: A method of assembling original material in two separate rolls, allowing optical effects to be made by double printing (A and B Printing). A OR B WIND: When a roll of 16 mm film, perforated along one edge, is held so that the outside end of the film leaves the roll at the top and toward the right, winding "A" should have the perforations on the edge of the film toward the observer, and winding "B" should have the perfo rations on the edge away from the observer. In both cases, the emulsion surface should face inward on the roll. A TAKES: Good takes. Also known as circle takes. A WIND: When you hold a roll of 16 mm or other singleperf film so that the film leaves the roll from the top and toward the right, the perfora tions will be along the edge toward the observer. ABRASION MARKS: Scratches on film caused by dirt, improper handling, grit, emulsion pileups, and certain types of film damage (e.g., torn per forations). ACADEMY APERTURE: In projection, the aperture cutout, designed as specified by the American Academy of Motion Picture Arts and Sciences that provides for a screenimage aspect ratio of approximately 1.37:1; also called "sound aperture." ACADEMY LEADER: A nonprojected identification and timing count down film leader designed to specifications of the American Academy of Motion Picture Arts & Sciences, and placed at the head end of a print reel. The countdown cuing information is related to "feet" which, in the silent days, meant projection at 16 frames per second, or 1 foot per sec ond. See UNIVERSAL LEADER. ACETATE: A slowburning base material frequently used for motion pic ture films. Also, in sheet form, for overlay eels. ACETATEBASE FILM: Any film with a support that contains cellulose tri acetate; safety film. ACTINIC LIGHT: Light that can form a photographic latent image or acti vate a photoelectric cell. ACTION: The movement of the subject within the camera field of view. The command given by a director. ADDITIVE LAMPHOUSE: A printer lamphouse consisting of three light sources, one for each color record. 119
ADDITIVE PRINTER: Prints from color originals or intermediates; uses red, green, and blue lights that are controlled separately to produce the correct compositecolor printing light for each shot in the film. ADDITIVE PRINTING: the use or three separate colored sources red, green, blue are combined to form the light source that exposes the film. Modern additive printers separate white light from a tungsten halogen bulb into its red, green and blue components by using a set of dichroic mirrors. ADJACENCY EFFECTS: Phenomena that alter the densityexposure rela tionship, enhancing the apparent sharpness of the image and causing modulation transfer values greater than 100 percent. ADO (AMPEX DIGITAL OPTICS): Trade name for digital effects system manufactured and sold by Ampex. ADVANCE: The separation between a point on the sound track of a film and the corresponding picture image. AERIAL IMAGE OR VIRTUAL IMAGE: An image focused by a projec tion lens near a field or relay lens. A camera lens is then used to form a real image on the film from the aerial image. A cell or another material can be placed at the aerialimage location to combine it with the aerial image on film. AGC (AUTOMATIC GAIN CONTROL): A circuit that automatically adjusts audio or video input levels. AGITATION: Keeping various solutions in motion while developing film. Agitation is necessary to achieve even solution action, or uniformity, and temperature consistency. ANALOG: An electrical signal that is continuously variable. ANALYTICAL DENSITY: Measurement of the amount of yellow, cyan, and magenta dye in an image. ANAMORPHIC IMAGE: An image that has been squeezed in one direction, usually horizontally, by an anamorphic lens. ANAMORPHIC LENS: A lens that produces a "squeezed" image on film in the camera. When the film is projected on a screen, an appropriate lens reverses the effect, and the image spreads out to lifelike proportions. Designed for widescreen movie photography and projection. ANAMORPHIC RELEASE PRINT: A print in which the images are com pressed horizontally. 120
ANGEL HAIR: Fine hairlike skiving, or slivers, caused when the film edge rubs against a sharp edge or burr in the projector. Also produced when excessive film/gate misalignment is present. ANGLE: With reference to the subject, the direction from which a picture is taken. The camerasubject relationship in terms of the immediate sur roundings. ANIMATION: The making of inanimate objects to appear mobile. This can be done by exposing one or two frames of movie film and then moving the objects slightly and exposing one or two more frames, etc. When the movie is projected, the objects will appear to have moved by them selves. ANIMATION CAMERA: A motion picture camera with special capability for animation work, which usually includes frame and footage counters, the ability to expose a single frame at a time, reversefilming capability, and parallaxfree viewing. ANIMATIC: Limited animation, consisting of artwork shot and edited to serve as a video tape storyboard. Commonly used for test commercials. ANIMATOR: An artist who uses the techniques of framebyframe film making to give his artwork the illusion of movement. In studio anima tion, the person responsible for drawing the moving characters; in inde pendent animation, the animator is generally responsible for all phases of production. ANSI: American National Standards Institute. ANSWER PRINT: The first print (combining picture and sound, if a sound picture), in release form, offered by the laboratory to the producer for acceptance. It is usually studied carefully to determine whether changes are required prior to printing the balance of the order. ANTICIPATION: A pause or small countermove made by a character in preparation for a major movement; used by animators to help give the illusion of a body moving with the proper sense of weight and balance. ANTIHALATION BACKING (COATING): A dark layer coated on or in the film to absorb light that would otherwise be reflected back into the emulsion from the base. APERTURE: (1) Lens: The orifice, usually an adjustable iris, which limits the amount of light passing through a lens. (2) Camera: In motion pic ture cameras, the mask opening that defines the area of each frame exposed. (3) Projector: In motion picture projectors, the mask opening that defines the area of each frame projected. 121
APERTURE PLATE: A metal plate containing the aperture that is inserted into a projector or camera. (NOTE: In some cameras, the aperture plate cannot be removed.) ARC LAMP: A lamp whose light source consists of an open carbon arc or a closed xenon arc. The light is generated in a gas ball between two elec trodes. ASA: Exposure Index or speed rating that denotes the film sensitivity, defined by the American National Standards Institution. Actually defined only for blackandwhite films, but also used in the trade for color films. ASPECT RATIO: Proportion of picture width to height such as 1.37:1 or 1.85:1, or 2.35:1. ATMOSPHERE SKETCH: A quick sketch, generally in color, made by the director or layout artist, to indicate the mood or style of a scene. AUTO ASSEMBLE: An operation in which a computer performs editing unaided, working from a previously edit decision list. AVERAGE GRADIENT: A measure of contrast of a photographic image , representing the slope of a portion of a characteristic curve. The term which refers to a numerical means for indicating the contrast or the pho tographic image. B WIND: When you hold a roll of 16 mm or other singleperf film so that the film leaves the roll from the top and toward the right; the perfora tions will be along the edge away from the observer. BACKGROUND: A flat piece of artwork that serves as the setting for the animated action, and which may vary from a realistically rendered scene to a sheet of colored paper. Abbreviated as BG or BKG. BACKGROUND LIGHT: The light or lights used to illuminate the back ground. BACKING: (1) Antihalation Backing: A temporary, darkcolored, gelatin coating which is sometimes applied to the rear side of a photographic plate or film to reduce halation by absorbing any light that may pass through the emulsion. (2) NonCurl Backing: A transparent, gelatin coating, sometimes applied to the opposite side of photographic film from the emulsion to prevent curling by balancing the forces that tend to curl the film as it is wet and dried during processing (3) Coating: (e.g. antiabrasion coating or remjet backing) applied to the base side of the film to improve characteristics and performance.
122
BALANCE STRIPE: A magnetic stripe on the opposite edge of the film from the magnetic track. Although the purpose of the stripe is to keep the film level on the reel, some projectors also use it for recording. BAR SHEET: A printed form, used by directors and animators in planning the movement of art and camera, on which all the elements of a filmmusic, voices, sound effects, visualsare charted framebyframe in their relationship to time. BARN DOOR: A frame with adjustable flaps, attached to the studio light to control unwanted spill light or the spread of the light beam. BARNEY: A lightweight padded covering that generally performs the same function as a blimp. Heated barneys are sometimes used to facilitate shooting under extremely cold outdoor conditions. BASE: The transparent, flexible support, commonly cellulose acetate, on which photographic emulsions are coated to make photographic film. BASE PLUS FOG: Density of the film support plus the silver or dye pro duced by the effects of the developer. Pertains only to an unexposed portion of the film. BEAT: The musical tempo (of the sound track) used for timing motion pic ture action. BELL AND HOWELL PERFORATION: A film perforation shaped with flat top and bottom and curved sides. BICYCLING: See CIRCUITING. BIPHASE: Electrical pulses from the tachometer of a telecine, used to update the film footage encoder for each new frame of film being trans ferred. BIPACK FILMING: The funning of two films simultaneously through a camera or optical printer, either to expose both or expose one through the other, using the one nearest to the lens as a mask. Often used in spe cialeffects work to combine live action with animated images. BLACK: The absence of all visible light. Also the absence of any distin guishable colors. BLACKANDWHITE FILM: A film which produces a monochromatic pic ture in shades of gray (usually a metallic silver image). BLACKBODY RADIATOR: A light source which has a continuous smooth spectral distribution. 123
BLACK LIGHT: Ultraviolet light. BLIMP: A soundproof enclosure that completely covers the camera to pre vent cameraoperating noise from being recorded on the sound track. BLINK: Density changes in the projected image; caused by studio light fluc tuation, printer or sensitometric problems, or radiation fog. BLOOPING: The technique of applying a special opaque ink or tape over the sound track at the splice in a wide triangular or circular pattern to pre vent soundtrack clicks and other annoying sounds caused by splices. BLOOPING INK: Used to opaque the section of a positive film splice in a sound track; to reduce the noise created as the splice passes over the projector sound head. BLOW UP: (part of frame) In transferring an image by means of an optical printer, it is possible to enlarge a properly proportioned fraction of the original image to full frame size in the copy, or to enlarge an original 16 mm image to 35 mm size. BLOWUP PRINTING: Optical printing resulting in a picture image size other than that of the original film. BLUESCREEN: The filming or videotaping of actors, props or objects in front of a bluescreen (or greenscreen). In postproduction, the blue or green is replaced by another element, such as background, using digital or optical special effects techniques. BOOM: A long, adjustable arm used to position a microphone during pro duction. BOTTOM LIGHTING: When the source of illumination for photographing a scene comes from beneath the artwork, rather than above it; used for a variety of reasons, such as the creation of glowing letters or stars, or to photograph several layers of drawings at once for a pencil test. Also known as Under Lighting. BOUNCE LIGHT: Light that is reflected off ceilings and walls to illuminate the subject indirectly. BREAKDOWN: The separation of a roll of camera original negative into its individual scenes. BREAKDOWN TABLE: A film handling unit that is one component of plat ter system. It is used to unload (break down ) the large film roll from the platter onto the individual shipping reels prior to shipment. The unit is also used in loading the platter (makeup). See MAKEUP TABLE. 124
BROAD LIGHT: Soft, floodlight type of illumination unit; usually not focusable. BUCKLE: Occurs when the perforated edges of film are shorter than the center; caused by the loss of solvent or moisture from the edges of the film during long storage. BURNIN: The photographic double exposure of a title or other subject mat ter over previously exposed film. BURRED TOOTH: Physical damage to a tooth on a projector sprocket. Usually caused by a blow from, or accidental contact with, a metallic object which causes a sharp protrusion to form on a tooth edge. BUTT SPLICE: Film splice in which the ends come together without over lapping; ends are held together by splicing tape. BUZZ TRACK: A sound test film with a specially made sound track that is used for determining the proper lateral positioning of the scanning beam slit in relation to film travel. CAMERA AXIS: Any imaginary line running exactly through the optical center of the camera lens. CAMERA LOG: A record sheet giving details of the scenes photographed on a roll of original negative. CAMERA OPERATOR: The person responsible for translating the instruc tions on the exposure sheet into camera moves and photographing the artwork. CAMERA ORIGINAL: Film exposed in a camera. CAMERASCOPE: A widescreen presentation process compatible with CinemaScopetype presentations. CANDELA (cd): International unit of luminance measurement (1 candela per square meter = 0.2919 footlamberts). CATALOG NUMBER: Identifies a particular product. CEL: A thin, flexible, transparent sheet of acetate, which has been punched, onto which the animators' finished drawings are transferredeither by inking or xerographyand painted. The clear eel does not show when photographed, so when it is placed over the background, the characters appear to be within the setting.
125
CEL ANIMATION:An animation technique in which the figures to be ani mated are drawn and painted on eels, placed over a background, and photographed frame by frame. Cel animation has been the standard technique for studio animation since its invention in 1915. CELL SIDE: The base (Celluloid) surface of a strip of film. CELLULOSE TRIACETATE: Transparent, flexible material used as a base support for photographic emulsions. CEMENT SPLICE: Film splice made by using a liquid solvent cement to weld the overlapping ends together. CEMENT SPLICER: Device used to make cement splices. Some cement splicers can also be used to make overlapping tape splices. CGI: Computer Generated Imagery. CHANGEOVER: In projection, the act of changing from one projector to another, preferably without interrupting the continuity of projection; or, the points in the picture at which such a change is made. CHARACTER ANIMATION: The art of making an animated figure move like a unique individual; sometimes described as acting through draw ings. The animator must understand how the character's personality and body structure will be reflected in its movements. CHARACTERISTIC CURVE: Shows the relationship between the exposure of a photographic material and the image density produced after pro cessing. CHECK: The step in production in which all elements of a scene are exam ined and checked against the exposure sheet to ensure they are correct before being filmed. In studio animation, the person responsible for this step is the Checker. CHECKERBOARD CUTTING: A method of assembling alternate scenes of negative in A and B rolls allowing prints to be made without visible splices. CHEMICAL SPLICE: See CEMENT SPLICE. CHIAROSCURO: The arrangement or treatment of light and dark parts in a pictorial work of art, or in a given frame of a motion picture. CHROMAKEY: A method of electronically matting or inserting an image from one camera into the picture produced by another. Also called "keying", the system uses a solid color background behind the subject to be inserted and signal processing through a special effects generator. 126
CHROMINANCE: The color portion of a video signal. CINCH MARKS: Short scratches on the surface of a motion picture film, running parallel to its length; these are caused by dust or other abrasive particles between film coils, or improper winding of the roll, permitting one coil of film to slide against another. CINCHING: Practice of pulling the end of a roll to tighten it. Not recom mended. CINEMASCOPE: Trade name of a system of anamorphic widescreen pre sentation. The first commercially successful anamorphic system for the presentation of widescreen pictures combined with stereophonic sound. The 35 mm negative camera image is compressed horizontally by 50 percent using a special anamorphic camera lens. Upon projection, the 35 mm print image is expanded horizontally by the same amount using a similar anamorphic projection lens. Depending on the type of sound used in the print, the screen image has an aspect ratio of 2:35:1 (optical sound), or 2:55:1 (4track magnetic sound). CINEMIRACLE: A widescreen presentation, as in Cinerama, that used three separate 35 mm film strips projected on a large, deeply curved screen. One of the main differences, however, was the consolidation of the three projectors in a single booth away from the audience. This was accomplished by the use of mirrors on the two outer projectors to main tain picture orientation. CINEON DIGITAL FILM SYSTEM: A new Kodak system which transfers images originated on film to a digital format for electronic compositing, manipulation and enhancement, and outputs back to film with no loss of image quality. CINEPANORAMIC: A widescreen process compatible with CinemaScope type presentations. CINERAMA: Originally, a widescreen presentation utilizing three separate 35 mm films, each containing one third of the total image (6 perfora tions high), and projected on a deeply curved and vertically slotted screen from three projectors located in booths on the main floor of the auditorium. The sense of involvement was extraordinary, but the ever present seams between the separate projected images were quite dis tracting. Current Cinerama presentations use 70 mm film containing a single image that is purposely distorted. During projection, the image distortion is corrected by the deeply curved screen and the original Cinerama sensation is recreated. CINEX STRIP: A short test print in which each frame has been printed at a different exposure level. 127
CIRCARAMA: A special presentation system used at Disneyland. The spec tators stand in the middle of a circle viewing a 360degree panorama on a surround screen 8 feet high and 40 feet in diameter made up of eleven panels. The original negatives are made on eleven 16 mm cameras arranged in a concentric circle. The prints are projected by a ring of interlocked 16 mm projectors. CIRCUITING: The practice of shipping feature releases directly from one theater to another without intervening inspection or repair. CLAPSTICKS: Two boards hinged at one end that are slapped together to indicate the start of a filming session (take). Used by editors in conjunc tion with a slate, which provides the corresponding visual cue, to syn chronize sound and image. CLAW: Mechanism used in most camera and projectors to move the film intermittently. CLAY ANIMATION: An animation technique involving the use of pliable clay figures that are manipulated before each exposure. CLEANUP: The process of retracing the animators' rough, sketchy drawings and converting them into finished drawings with smooth outlines that can be transferred to eels. In studio animation, this is done by the Cleanup Artist. See also roughs. CLICK TRACK: A timing device used when elements of the sound track are added after the animation has been completed. The beat to which the animation is matched is recorded onto tape and played through ear phones for the conductor, sound effects creator, and/or voice artists, enabling them to match their sounds to the film. CLOSEUP: A detail photographed from such a distance that only a small portion of the subject fills a frame of film. CLUTCH: A mechanical device used to transfer rotational motion from a power source to a driven source. In projectors, the device on the takeup spindle that is used to adjust the tension on the film during take up. When using reels with a hubtorim ratio of more than 1:3, the clutch adjustment can be critical if film damage is to be avoided. COATED LENS: A lens covered with a very thin layer of transparent mater ial that reduces the amount of light reflected by the surface or the lens. A coated lens usually transmits more light than an uncoated lens at the same fstop, because of less flare. COLD MIRROR: An interference coated mirror in a lamphouse which does not reflect the infrared rays. 128
COLLIMATED: A beam of light is said to be collimated when all of its rays have been made parallel. COLOR ANALYZER: A device for determining the correct printing light ratios for printing color negatives. COLOR BALANCE: The perceptual appearance of a color image of film as a function of the ration of exposures of each of these primary color records on the film. COLOR BURST: A sample of the color subcarrier that is inserted into the horizontal blanking interval at the start of each line of video. COLOR CORRECTION: The altering of the color balance by modifying the ratio of the printing light values. COLOR DUPLICATE (DUPE) NEGATIVE: Duplicate with a negative color image; made from a negative color original. Typically used for making release prints. COLOR FILM: Color film carries one or more emulsions which after pro cessing. COLOR INTERNEGATIVE: Negativeimage color duplicate made from a positive color original. Typically used for making release prints. COLOR NEGATIVE: A negative (opposite) record of the original scene. Colors are the complementaries of the colors in the scene; light areas are dark, and dark areas are light. COLOR POSITIVE: A positive record of the original scene. COLOR PRINT FILM: Film designed for making positive prints from color originals and color duplicates. COLOR REVERSAL FILM: Film that after processing has a color positive image. Can be an original camera film or a film in which other positive films are printed. COLOR REVERSAL INTERMEDIATE: Color duplicate negative made by the reversal process directly from an original color negative. COLOR SATURATION: A term used to describe the brilliance or purity of a color. When colors present in a film image are projected at the proper screen brightness and without interference from stray light, the colors that appear bright, deep, rich, and undiluted are said to be saturated.
129
COLOR SENSITIVITY: Portion of the spectrum to which a film is sensitive. The ability of the eye or photographic stock to respond to various wave lengths of light. COLOR SEPARATION NEGATIVE: Blackandwhite negative made from red, green, or blue light from an original subject or from positive color film. COLOR TEMPERATURE: The color quality expressed in degrees Kelvin (K) of the light source. The higher the color temperature, the bluer the light; the lower the temperature, the redder the light. COLOR TEST: Footage of a film that has been timed and which is used as a check to make sure that colors, characters, and backgrounds do not clash in the finished film. See timing. COMBINED NEGATIVE: Negative film containing the picture and the sound track. COMPLEMENTARY COLOR: Color that is minus one of the primary col ors. Cyan is minus redcyan and red are complementary colors; yellow is minus blueyellow and blue are complementary colors; magenta is minus greenmagenta and green are complementary colors. Produces white when mixed in equal parts with the primary color to which it is complementary. COMPONENT VIDEO: A system of signal recording and processing that maintains the original video elements separately rather than combined (encoded) into a single, composite signal. COMPOSITE PRINT: A print of a film that contains both picture and sound track. Films regularly shown in theaters are composite prints. Also called Release Print. COMPOSITE VIDEO: A video signal in which the luminance and chromi nance elements have been combined, as is NTSC, PAL and SECAM. COMPOSITING: The process of combining two or more separate images into a single, new image. COMPOSITION: The distribution, balance, and general relationship of masses and degrees of light and shade, line, and color within a picture area. COMPOUND: The flat, table like part of an animation stand, on which the artwork rests while it is being photographed.
130
COMPUTER ANIMATION:A field of animation that takes advantage of the computer's ability to direct and generate a video image based on pre programmed input. CONFORM: Match the original film to the final edited work print. CONTACT PRINT: Print made by exposing the receiving material in contact with the original. Images are the same size as the original images, but have a reversed lefttoright orientation. CONTACT PRINTER: Printer in which the two pieces of film are in contact, usually emulsiontoemulsion, during exposure. CONTINUITY: The smooth flow of action or events from one shot or sequence to the next. CONTINUOUS CONTACT PRINTER: A printing machine where the emul sion of the negative film is in direct physical contact with the positive raw stock emulsion, and the two films are moving continuously across the printing aperture. CONTINUOUS MOTION PROJECTOR: A projector in which the film moves through the projector gate in nonintermittent motion. CONTRAST: (1) The general term for describing the tone separation in a print in relation to a given difference in the lightandshade of the nega tive or subject from which it was made. Thus, "contrast" is the general term for the property called "gamma" (Y), which is measured by mak ing an H & D Curve for the process under study. (2) The range of tones in a photographic negative or positive expressed as the ratio of the extreme opacities or transparencies or as the difference between the extreme densities. This range is more properly described as "scale" or "latitude." (3) The ability of a photographic material, developer, or process as a whole to differentiate among small graduations in the tones of the subject. CONTROL STRIP: A short length of film containing a series of densities to check on laboratory procedures. COOKIE (kukaloris): A thin panel with regular or irregular shapes cut out, permitting light directed through it to form a pattern on a background. CORE (Film): A plastic cylinder on which film is wound, shipped and stored. CORRECTION FILTER: A medium enabling a color change.
131
COUNTERCURRENT WASH: Wash water that is flowing through several interconnected tanks in the opposite direction to the film travel. The inlet pipe is usually situated near the bottom of the tank and the over flow at the waterline near the film entrance. COUPLER: A chemical incorporated in the emulsion of color film stocks which produces a dye image associated with the developed silver image. CRANE: The mounting that supports the camera over the compound. CREASES: A crease is defined as a distinct sharp foldline or crack in a piece of film. CREDITS: Titles of acknowledgement for the production. CRT: Color Reversal Intermediate, a duplicate color negative prepared by reversal processing. CROPPING: To change, delete, or otherwise alter the size of an image being projected or viewed as a print. In theatrical projection it is usually the result of "home made" aperture plates, improper screen masking, wrong focal length lenses, etc. CROSS ABRASIONS: Short scratches across the film width that occur when sections of the roll shift from sidetoside during shipment. CROSS MODULATION TEST: A test designed to measure the degree of the unwanted image spread in a photographic variablearea sound nega tive and its cancellation by the positive print. CURL: A defect of a photographic film consisting of unflatness in a plane cutting across the width of the film. Curl may result from improper dry ing conditions, and the direction and amount of curl may vary with the humidity of the air to which the film is exposed. CURTAINS: Nonuniform densities that run lengthwise on the projected image; caused by inadequate agitation during predevelopment and development. CURVE (H&D): The characteristic curve developed by Hurter and Driffield that depicts how faithfully a photographic emulsion has reproduced the tonal scale of the original scene. CUT: (1) The instantaneous change from one scene to another. Successive frames contain the last frame of one scene and the first frame of the fol lowing scene. (2) To stop operation of camera, action, and/or sound recording equipment. (3) To sever or splice film in the editing process. 132
CUTTING: The selection and assembly of the various scenes or sequences of a reel of film. CYAN: Bluegreen; the complement of red or the minusred subtractive used in threecolor processes. CYCLE: A series of drawings that are photographed again and again. The last drawing moves logically into the first, to create the appearance of continuous, repetitive motion. Cycles are normally used for movements that are repeated without variation, such as walks or runs. D LOG H CURVE: The curve showing the relation between the logarithm of the exposure and the resultant density on processed film. Dl: Component video in the 19mm digital cassette format. D2: Composite video in the 19mm digital cassette format. D3: Composite video in the halfinch digital cassette format. D4: Ommited; an obscenity in Japan. D5: Component video in the halfinch digital cassette format. DLOG E: (Density vs the log of exposure) The graph made by plotting the density of a film sample against the log of the exposure that made that density. Also known as DLog H and H and D curve. DLog H (H for exposure) is the technically correct term. DMAX: See Maximum Density. DMIN: See Maximum Density. DAILIES: Picture and sound work prints of a day's shooting; usually an untimed onelight print, made without regard to color balance. Produced so that the action can be checked and the best takes selected; usually shown before the next day's shooting begins. DATASHEET: A publication giving technical details of a specific film prod uct. DAYLIGHT: Light consisting of a natural combination of sunlight and sky light (approximately 6500 degrees K). DECIBEL (dB): Unit of loudness measured on a logarithmic scale. The human ear can perceive 1 dB changes in loudness in the aural range. DEFINITION: The clarity or distinctness with which detail of an image is rendered; fidelity of reproduction of sound or image. 133
DELRAMA: A widescreen process compatible with CinemaScopetype pre sentations DENSITOMETER: Instrument used to measure the optical density of an area in a processed image by transmittance or by reflectance. DENSITOMETRY: Science of measuring the lightstopping characteristics of film or filters. DENSITY: Lightstopping characteristics of a film or a filter. The negative logarithm to the base ten of the transmittance (or reflectance) of the sample. A sample which transmits 2 of the incident light has a transmit tance of 0.50, or 50 percent and a density of 0.30. DEPTH OF FIELD: The range of object distances within which objects are in satisfactory sharp focus in a photograph. DEPTH OF FOCUS: The range through which a photographic film or plate can be moved forward and backward with respect to the lens while retaining satisfactory sharp focus on an object at a given distance. DESIGNER: In studio animation, the person responsible for the overall look and style of the film. DEVELOPER: A solution used to turn the latent image into a visible image on exposed films DEVELOPMENT: Process of making a visible film image from the latent image produced during exposure. DIAGONAL SCRATCHES: Slanted cross scratches on the film usually caused by the film riding over the edge of a roller flange. More common in platter transport systems. DIALOGUE: The portion of the sound track that is recorded by the voice artists and spoken by the characters on the screen. DIAPHRAGM: An adjustable opening mounted behind or between the ele ments or a lens used to control the amount of light that reaches the film. Openings are usually calibrated in fnumbers. DICHROIC INTERFERENCE MIRROR: Mirror with layered coatings designed to control spectral light qualities; absorbs certain frequencies and transmits others.
134
DICHROIC: A type of coating that when applied to glass can produce a so called "cold" mirror for use in projector lamphouses that permits greater screen brightness without the risk of radiant energy (heat) problems. Usually, the rear surface of the mirror is treated by depositing very thin layers of a special coating material designed to transmit infrared (IR) radiation effectively and reflect visible radiation. Alternatively, by selecting certain other materials for the deposit, IR radiation can be reflected and visible radiation transmitted, thus providing an efficient heat filter for arc radiation devices. DIFFRACTION: The spreading of light as it passes the edges of opaque objects or through narrow slits. Light also is diffracted when passing through a lens. The effects of this distortion on images is greater as the aperture becomes smaller. DIFFUSION: The spreading of light rays from a rough reflecting surface or by transmission of light through a translucent material. DIGITAL: A system whereby a continuously variable (analog) signal is bro ken down and incoded into discrete binary bits that represent a mathe matical model of the original signal. DIGITAL EFFECTS: Special effects, such as picture compression, rotation, reversal, etc., performed with a digital effects system. DIGITAL RECORDING: Soundrecording process in which sound waves are recorded as digital bits. During playback, a digitaltoanalog conver sion occurs that changes the digital bits back into sound waves. Digital recording produces highquality true sound that does not contain any system noise. DIGITAL VIDEOTAPE: A format which stores an image on tape as a binary code, allowing it to be moved through various digital devices with mini mal loss of quality. Current storage formats are Dl, D2, D3. DIGITAL STORAGE DEVICE: A device using magnetic or optical disks to store and retrieve digital images and/ or information. DIMENSION 150: A special 70 mm system developed in 1963 that consist ed of special optics used in printers and projectors. The manufactured prints could be shown on deeply curved screens such as those used in Cinerama. DIMMER: An electrical device, normally in the form of variable resistance or load, that reduces electrical energy to a lamp, usually by reducing voltage. DIRECTOR: The person who interprets the written book or script. He over sees all aspects of the production. 135
DISHING: Occurs when a loosely or tightly wound roll of film slips edge wise to form a concave/convex dish like form. DISK STORAGE DEVICE: A device using magnetic or optical disks to store and retrieve digital images and/or information. DISSOLVE: An optical or camera effect in which one scene gradually fades out at the same time that a second scene fades in. There is an apparent double exposure during the center portion of a dissolve sequence where the two scenes overlap. DISTRIBUTOR: Firm that sells, leases, and rents films. DOLBY SYSTEM: Trade name for an audio noisereduction system. DOLLY: (1) A truck built to carry camera and camera operator to facilitate movement of the camera during the shooting of scenes. (2) To move the camera toward or away from the subject while shooting a scene. DOUBLE (MULTIPLE) EXPOSURE: The photographic recording of two (or more) images on a single strip of film. The images may be either superimposed or side by side in any relationship, sometimes individual ly vignetted. DOUBLEFRAME: Identical views photographed twice (two frames) instead of once. This technique cuts in half either the speed of a move ment or the number of drawings required for a complete action, some times called "on twos." DOUBLE SYSTEM RECORDING: Synchronous sound recording on a recorder that is separate from the camera. Recorders are typically mag netic with syncpulse capability. DOUBLE SYSTEM SOUND: Recording of sound on tape and picture on film; synchronization occurs during editing. DROP FRAME: A type of SMPTE time code designed to match clock time exactly. Two frames of code are dropped every minute, on the minute, except every tenth minute, to correct for the fact that color frames occur at a rate of 29.97 per second, rather than an exact 30 frame per second (see NonDrop Frame). Designed to drive editors crazy! DUBBING: The combination of several sound components into a single recording. DUBRAYHOWELL PERFORATION: A general purpose rectangular film perforation having the width of a positive perforation and the height of a negative perforation. 136
DUPE, DUPE NEGATIVE: A duplicate negative, made from a master posi tive by printing and development or from an original negative by print ing followed by reversal development. DUSTING: The formation and accumulation of fine particles in the projector gate area. Can be caused by material scraped from the film due to mis alignment of film in the gate, excessive tension, lack of proper lubrica tion, etc. See Angel hair. DYE: In photography, the result of color processing in which the silver grains or incorporated color couplers have been converted into the appropriate dye to form part of the color image. EBERHARD EFFECT: See Adjacency Effect EDGE DAMAGE: Physical damage of the edge of a film or the perforation. EDGE GUIDE: A fixed edge or shoulder against which the film is physically pressed to ensure steadiness in the lateral direction. EDGE NUMBERS: (Key Numbers / Footage Numbers) Sequential numbers printed along the edge of a strip of film by the manufacturer to desig nate identification. EDGEWAX: Waxing method recommended for lubricating release prints; treatment is with a solution of 50 grams of paraffin wax per litre of trichloroethane applied only to the edges of the emulsion side of the film. EDGEWEAVE: Occurs when one or both of the edges (along the length of the film) are longer than the center. EDIT: To arrange the various shots, scenes, and sequences, or the elements of the sound track, in the order desired to create the finished film. EDIT SYNC (LEVEL SYNC) (EVEN SYNC): The relation between the pic ture and sound records during editing, when they are in alignment and not offset as for projection. EDITING: The process of selecting the shots and sequences that will be included in the final film, their length, and the order in which they will appear. EDITOR: The individual who decides what scenes and takes are to be used, how, where, in what sequence, and at what length they will appear. EDL (EDIT DECISION LIST): List of edits prepared during offline editing.
137
EMBOSSING: A permanent film deformation caused by repeated projec tions with very highintensity lamps. This distortion has not been observed to have a detrimental effect on screen image quality. EMULSION, EMULSION LAYER: (1) Broadly, any lightsensitive photo graphic material consisting of a gelatin emulsion containing silver halides together with the base and any other layers or ingredients that may be required to produce a film having desirable mechanical and photographic properties. (2) In discussions of the anatomy of a photo graphic film, the emulsion layer is any coating that contains light sensi tive silver halides grains, as distinguished from the backing, base, sub stratum, or filter layers. EMULSION NUMBER: A number identifying a complete coating from a single emulsion batch or mixture. EMULSION SIDE: The side of a film coated with emulsion. EMULSION SPEED: The photosensitivity of a film, usually expressed as an index number based on the film manufacturer's recommendations for the use of the film under typical conditions of exposure and develop ment. ENCODER: A circuit that combines the primary red, green and blue signals into a composite video signal. EQUIVALENT NEUTRAL DENSITY (END): Form of analytical neutral density that describes image color directly. ESTAR BASE: The trade name applied to the polyethylene terephthalate film base manufactured by Eastman Kodak Company. EXCHANGE: A depository and inspection/distribution center for theatrical release prints. Exchanges are located in approximately 35 regional areas within the United States roughly dependent on theater and population density. EXISTING LIGHT: Available light, Strictly speaking, existing light covers all natural lighting from moonlight to sunshine. For photographic pur poses, existing light represents the light that is already on the scene or project and includes room lamps, fluorescent lamps, spotlights, neon sighs, candles, daylight through windows, outdoor scenes at twilight or in moonlight. EXPOSURE: Amount of light that acts on a photographic material; product of illumination intensity (controlled by the lens opening) and duration (controlled by the shutter opening and the frame rate).
138
EXPOSURE INDEX (El): Number assigned to a film that expresses its rela tive sensitivity to light. The El is based on the film emulsion speed, a standard exposure technique, and specific processing solutions. EXPOSURE LATITUDE: Degree to which film can be underexposed or overexposed and still yield satisfactory results. EXPOSURE METER, INCIDENT: A meter calibrated to read and integrate all the light aimed at and falling on a subject within a large area. (Scale may be calibrated in footcandles or in photographic exposure settings.) EXPOSURE METER, REFLECTANCE: A meter calibrated to read the amount of light, within a more restricted area, reflecting from the sur face of a subject or an overall scene. (Scale may be calibrated in foot candles or in photographic exposure settings.) EXPOSURE SETTING: The lens opening selected to expose the film. EXPOSURE SHEET: The framebyframe instructions for the camera opera tor that accompany the artwork when it is sent to be photographed. fNUMBER: A symbol that expresses the relative aperture of a lens. For example, a lens having a relative aperture of 1.7 would be marked f/1.7. The smaller the fnumber, the more light the lens transmits. FADE: Exposure of motion picture film either in the camera or during sub sequent operations, so that, for a fadein, starting with no exposure and extending for a predetermined number of frames, each successive frame receives a systematically greater exposure that the frame preced ing it, until full normal exposure for the scene has been attained. From this frame on, successive frames receive identical exposure for the remainder of the take. FALLOFF: The gradual reduction in luminance from the screen center to the edges and corners. FAST: (1) Having a high photographic speed. The term may be applied to a photographic process as a whole, or it may refer to any element in the process, such as the optical system, emulsion, developer. (2) Resistant to the action of destructive agents. For example, a dye image may be fast to light, fast to heat, or fast to diffusion. FEATHERED LIGHT: A light moved off axis so that only the weaker edge of the light pattern strikes the subject. A natural shading or falloff results. FERROTYPING: Mottled emulsion caused by improper final drying or con densation on a roll of film. 139
FIELD OF VIEW: The portion of the scene in front of the camera represent ed within the limits of the camera aperture at the focal plane. Area of field thus varies with focal length of lens and cameratosubject dis tance. FIELD (VIDEO): Onehalf of a complete picture (or frame), containing all the odd or even scanning lines of the pictured, In television, one of two complete sequences of raster lines forming an image. FILL LIGHT: Light used to fill in shadows. FILM (motion picture film): A thin, flexible, transparent ribbon with perfora tions along one or both edges; it bears either a succession of images or a sensitive layer capable of producing photographic images. See Raw stock. FILM BASE: Flexible, usually transparent, support on which photographic emulsions are coated. FILM CAN: Metal container designed to hold rolls, spools, or reels of motionpicture f ilms. FILM CEMENT: A special combination of solvents and solids used to make overlap splices on motion picture film by its solvent action and subse quent welding of the film at the junction. FILM EXCHANGE: See Exchange. FILM FOOTAGE ENCODER TIME CODE GENERATOR: An electronic device which takes the input form a Keykode numbers reader, decodes this information and correlates the numbers with the SMPTE time code it generates. This data, along with 3:2 pulldown status of the transfer, footage count and audio time code (if applicable) are made available for window burnins, VITCLTC recording and RS232 output to a com puter. (See Kodak PostProduction Flowchart) FILM GATE: Components that make up the pressure and aperture plates in a camera, printer, or projector. FILM GAUGE: Width of the standard sizes of motion picture films. FILM IDENTIFICATION CODE: Letter which identifies film type. FILM NUMBER: An identification code number given to every film prod uct. FILMTOTAPE TRANSFER: The process of transferring an image cap tured on film to videotape. 140
FILM PATCH: Transparent material used to repair film damage such as bro ken perforations, etc. FILM PERFORATION: Holes punched at regular intervals for the length of film, intended to be engaged by pins, pegs, and sprockets as the film is transported through the camera, projector, or other equipment. FILM SPEED: See "Emulsion Speed." FILM WEAVE: The lateral displacement or irregular and undesirable move ment of the film as it passes through the gate of a camera projector. FILTER: A piece of glass, gelatin or other transparent material used over the lens or light source to emphasize, eliminate or change the color or den sity of the entire scene or certain elements in the scene. FILTER LAYER: In a photographic film, a thin, uniform, colored layer that is coated above or below the emulsion to serve as a light filter; it con trols the spectral quality of the light reaching the emulsion. FINAL CUT: Last editing of a workprint before conforming is done or before sound workprints are mixed. FINE GRAIN: Emulsion in which silver particles are very small. FIRST PRINT: The first trial composite (married) print containing both pic ture and sound for the purpose of checking picture and sound quality. FIXING BATH (HYPO): A solution that removes any nonexposed silver halide crystals in the film. In addition, with color films, the silver is removed from the exposed area, leaving only the imageforming dyes. FLAG: See GOBO. FLAKING: The removal (chipping away) of emulsion particles from the edges of the film that tend to redeposit in the image area while the film is going through the projector gate. Flaking is cased by a lack of proper edgewax lubrication. FLANGE: The rim on a roller used for guiding the film. Also, a large disc used on a rewind to take up film on a core. A pair of flanges (discs) that screw together is called a split reel. FLASHING: Technique for lowering contrast by giving a slight uniform exposure to film before processing.
141
FLAT: An image is said to be "flat" if its contrast is too low. Flatness is a defect that does not necessarily affect the entire density scale of a repro duction to the same degree. Thus, a picture may be "flat" in the high light areas, or "flat" in the shadow regions, or both. FLUTE: See Edgewave. FLUTING: Effect of swelling on the outside film edges. FLUTTER: In sound, rapid period variation of frequency caused by unsteadiness of the film or tape drive. FLYSWATTERS: See GOBO. FOCAL LENGTH: The distance from the optical center of a lens to the point at which parallel rays of light passing through it converge (the focal point). FOCAL PLANE: The area in space on which parallel rays of light refracted through a lens focus to form sharp images. FOCUS: To adjust a lens so that it produces the sharpest visual image on a screen, on a camera film plane, etc. FOG: Darkening or discoloring of a negative or print, or lightening or discol oring of a reversal material. Causes include accidental exposure to light or Xrays, overdevelopment, using outdated film, and storing film in a hot, humid place. FOLEY: Background sounds added during audio sweetening to heighten realism, e.g., footsteps, bird calls, heavy breathing, short gasps, etc. FOLLOW FOCUS: To change the focus setting of a lens as a scene is being photographed to keep a moving subject in sharp focus. FOOTAGE: A method of measuring film length and therefore, screen time. As 90 feet of 35 mm film equal one minute of screen time, 35 mm footage is used in many studios as a measure of an animator's weekly output. Animators also refer to the length of scenes in feet, rather than in seconds or minutesa 30foot scene, rather than a 20second one. FOOTAGE NUMBERS: Also called edge numbers. Sequential numbers which are preexposed or printed in ink at regular intervals on the edge of the film outside or in between the perforations. FOOTLAMBERT: US luminance measurement unit (1 footlambert = 3.425 candelas per square meter). See Candela.
142
FORCEPROCESS: Develop film for longer than the normal time to com pensate for underexposure. FOREGROUND: The part of the scene in front of the camera, represented within the limits of the camera aperture, occupied by the object(s) near est to the camera. FOREHARDENED FILM: Any of the films designed for hightemperature processing. FORMAT: The size or aspect ratio of a motion picture frame. FPM: Feet Per Minute, expressing the speed of film moving through a mech anism. FPS: Frames Per Second, indicating the number or images exposed per sec ond. FRAME: The individual picture image on a strip of motion picture film. FRAMEBYFRAME: Filming in which each frame is exposed separately, as the object being photographed must be altered before each exposure in order to create the illusion of movement in the finished film; as opposed to the more usual method of filming in which the film runs through the camera at a steady, prescribed rate to record action taking place before it. FRAME COUNTER: An indicator which shows the exact number of frames exposed. FRAME LINE: The separation between adjacent image frames on motion picture film. FRAME LINE MARKING: A mark placed on the edge of the film between every fourth perforation as an aid to splicing in frame when no image or frame line is visible. On 70 mm film, a small punched hole placed between every fifth perforation. FRAME (VIDEO): A complete television picture made up of two fields, pro duced at the rate of approximately 29.97 Hz (color), or 30Hz (black& white). FRAMESTORE: A digital device designed to store and display a single tele visions frame as a "freeze frame". (See also Still Store) FREEZE FRAME: An optical printing effect in which a single frame image is repeated so as to appear stationary when projected.
143
FREQUENCY RESPONSE: Ability of the photographic sound track to reproduce the full spectral range of sounds. FRONT END: General terms for all production and preparation work up to the Answer Print stage before Release Printing. FULLCOAT: Magnetic film that is entirely covered on one side with the recording medium. GAIN, SCREEN: The measure of a screen's ability to reflect the light inci dent to it. A perfect screen would reflect back all the light that was inci dent to it at all angles. Such a screen would have a gain of 1.0. In practi cal use, however, most matte screens that allow wide viewing angles have a gain of about 0.85. Special metallized or directional screens can provide up to about 15 times more reflected light than a common matte screen, but their viewing angles are generally very limited, making them unsuitable for most theatrical applications. GAMMA: Measurement of the contrast of an image, representing the slope of the straightline portion of the characteristic curve. GATE: The aperture assembly at which the film is exposed in a camera, printer or projector. GATE TENSION: The resistance to film movement produced by adjustable springloaded rails in the projector gate. GAUGE: Refers to the format of the film stock, i.e., super 8, 16 mm, or 35mm. GELATIN FILTER (GEL): A light filter consisting of a gelatin sheet in which lightabsorbing pigment or dye is incorporated. GENEVA MOVEMENT: A mechanical device that produces intermittent film movement in the projector. The principle behind the movement involves a rotating cam and pin that intermittently engages in a four slotted star wheel, also known as a Geneva cross or Maltese cross. During the pin/slot engagement, the star wheel shaft containing the intermittent sprocket rotates 90°, or one frame. At normal projection speed, this intermittent rotation occurs 24 times per second. GENLOCK: A system whereby the internal sync generator in a device, such as a camera, locks on to and synchronizes itself with an incoming signal. GLOVE: A white, lintless, cotton glove used when handling motion picture raw stock and new release prints in the laboratory. Should be used in all film handling situations and changed frequently.
144
GOBO: Panel of opaque material on a footed stand with an adjustable arm. Used to confine the area a light illuminates, or to keep light from shin ing directly into the camera lens. GRAININESS: The character of a photographic image when, under normal viewing conditions, it appears to be made up of distinguishable parti cles, or grains. This is due to the grouping together, or "clumping" of the individual silver grains, which are by themselves far too small to be perceived under normal viewing conditions. GRANULARITY: Nonuniformity in a photographic image that can be mea sured with a densitometer. GRAY CARD: A commercially prepared card that reflects 18 percent of the light hitting it. Visually it appears neutral, or a middle gray halfway between black and white. "GREEN" PRINT: A newly processed print on which the emulsion may still be a little soft. If projected the first time without proper edgewax lubri cation, perforation damage can result. GROOVED TOOTH: A tooth on the intermittent sprocket that has a groove worn at the base on the pulldown side as a result of wear. It normally appears on all the teeth. The sprocket should be replaced although film damage does not always occur immediately. GROSS FOG: The density of the base of the film plus the density of the fog in the emulsion. Also known as Dmin and base + fog. GUIDE RAILS: Vertical rails located on both sides of the projector trap that restrict lateral movement of the film as it passes through the projector gate. GUIDE ROLLER: Any roller with flanges that is used to guide or restrict the position of motion picture film as it moves through a camera, projector, or printer. GUILLOTINE SPLICER: Device used for buttsplicing film with splicing tape. H&D CURVE: The graph made by plotting the density of a film sample against the log of the exposure that made that density. Named after Messrs. Hurter and Driffield who created the science of sensitometry. HALATION: A defect of photographic films and plates. Light forming an image on the film is scattered by passing through the emulsion or by reflection at the emulsion or base surfaces. This scattered light causes a local fog which is especially noticeable around image of light sources or sharply defined highlight areas. 145
HALIDE: Compound with a halogen, such as chlorine, bromine, iodine. HARD: (1) As applied to a photographic emulsion or developer, having a high contrast. (2) As applied to the lighting of a set, specular or harsh, giving sharp dense shadows and glaring highlight. HARD LIGHT: Light made up of directional rays of light that creates strong, hard, welldefined shadows; sometimes called specular light. HARRY:The trade name for a highly sophisticated and versatile digital effects system manufactured by Quantel. Used to create two and three dimensional animated graphic, transpose and transform objects and change colors. (See also Paintbox) HAZE FILTER: These filter provide varying degrees of bluelight and greenlight absorption. HDTV: High Definition Television, a recently developed video format with a resolution approximately twice that of standard television. HEAD END, HEADS: The beginning of a reel where the film image is upside down when the film is threaded into a projector for showing. HEAD RECORDING: On a tape recorder, printer or projector an electro magnet across which the tape or film is drawn and which magnetizes the coating on the tape base during recording. HEAT FILTER: An optical device that absorbs or reflects the nonvisible heat energy radiating from the arc lamp source before it reaches the film plane of the projector. See Dichroic. HEATER BARNEY: Padded camera cover with electric heating elements; used for coldweather filming. HERTZ (HZ): Unit of frequency; 1Hz = 1 cycle per second. HIGHSPEED CAMERA: A camera designed to expose film at rates faster than 24 frames per second. Used to obtain slowmotion effects. HIGHLIGHTS: Visually the brightest, or photometrically the most luminant, areas of a subject. In the negative image, the areas of greatest density; in the positive image, the areas of least density. HMI LIGHTS: Metal halide lamps are fundamentally mercury arcs with metal halide additives to adjust the color balance. Usually rated at approximately 5400 K. For daylightbalanced films. HOLD: To freeze or stop the action. To achieve a hold in animation, the same eel or position of an object is photographed for several frames. 146
HOT: Referring to too much light in an area, or to an excessively bright highlight. HUE: Sensation of the color itself; measured by the dominant wavelength. HUMIDITY: A term referring to the presence or absence of moisture in the air. For instance, low humidity describes conditions in a desert. Conversely, high humidity is related to tropical rain forest conditions. HYPO (FIXER): The name for fixing bath made from ammonium or sodium thiosulfate, other chemicals and water; often used as a synonym for fix ing bath. IDLE ROLLER: Free turning nonsprocketed rollers for guiding film through its appropriate path. ILLUMINANT: Light source used to project the film image or to expose the film. IMAGE, LATENT IMAGE: The invisible image formed in a camera or printer by the action of light on a photographic emulsion. IMAGE ORIENTATION: Laboratory function that assures that the projected image is properly formed on the screen, and that the sound track is on the appropriate side of the film. IMAGE SPREAD: Exposure slightly beyond the edges of the images formed by light striking the film. IMAGE STRUCTURE: Measurement of the capacity of an emulsion to record detail faithfully. IMBIBITION PRINT: A color print produced by the transfer of magenta, cyan, and yellow dyed matrix films in register on a specially prepared clear film base or paper Technicolor process and KODAK Dye Transfer process. INBETWEENS: The drawings that fall between the extreme points of a movement. In studio animation, these drawings are done by an assistant animator or inbetweener. See also extremes. INDEPENDENT: An animator who chooses not to be part of a studio, but works alone to produce his or her films. INFRARED: Nonvisible, long wavelength radiation from a carbon or xenon arc that contributes to the heating of the film and equipment.
147
INTEGRAL DENSITY: Measurement of how incident light is affected by the integral absorption of the color image rather than by the individual dye. INTEGRAL DYE MASKING: Using a different colored coupler to improve color rendition; masking couplers produce brighter, more saturated col ors while maintaining neutral. INTENSITY, LIGHT: A term referring to the power (strength) of a light source . . . the total visible radiation produced by the light source. INTERLOCK: A system that electronically links a projector with a sound recorder; used during postproduction to view the edited film and sound track, to check timing, pacing, synchronization, etc. INTERMEDIATE: Film used only for making duplicates from which other duplicates or prints are made. Does not include camera films. INTERMEDIATE SPROCKET: An intermittently rotated sprocket which positions the film in the aperture of a projector and moves it after the exposure cycle. INTERMITTENT: Not continuous but equally spaced (sometimes random) motion, as the intermittent (24 fps) motion of film through a projector. INTERNEGATIVE (DUPE NEGATIVE): Color negative made from a color negative. For making release prints. INTERPOSITIVE: A color master positive print. IN THE CAN: Describes a scene or program which has been completed. Also, "That's a wrap". INFRARED: Nonvisible radiation from the long wavelength portion of the spectrum. INSERT EDIT: An electronic edit in which the existing control track is not replaced during the editing process, The new segment is inserted into program material already recorded on the video tape. INTERLACE: The manner in which a television picture is composed, scan ning alternate lines to produce one field, approximately every 1/60 of a second in NTSC. Two fields comprise one television frame. Therefore, the NTSC television frame rate of approximately 30fps. INTERMITTENT MOVEMENT: The mechanism or a camera, printer or projector by which each frame is held stationary when exposed and then advanced to the next. 148
IPS: Inches Per Second. ISO: International Standards Organization. The international version of ANSI. JAMSYNC: Process of synchronizing a secondary time code generator with a preselected master time code, i.e., synchronizing the smart slate and the audio time code to the same clock. K: Degrees Kalvin, the unit of the color temperature scale. KEYKODE NUMBER: Kodak's machinereadable key numbers, Includes 10digit key number, manufacture identification code, film code and offset in perforations. KEYKODE READER: Device attached to a telecine or part of a bench log ger which reads bar code from motion picture film and provides elec tronic output to a decoder. KEY POSE: The characteristic or main pose in a movement. KEYSTONING: A geometrical image distortion resulting when a projected image strikes a plane surface at an angle other than perpendicular to the axis of throw, or when a plane surface is photographed at an angle other that perpendicular to the axis of the lens. KICKER: See SEPARATION LIGHT. KINESCOPE: A film of a video tape made by shooting the picture on a spe cially designed television monitor. Also referred to as Kine. KINETOSCOPE: An early filmstrip device developed and devised by Thomas Edison and W. K. L. Dickson. KUKALORIS: See COOKIE. LABORATORY: A facility that specializes in processing and printing film, sometimes offering additional services such as editing and film storage. LABORATORY FILM: Film products, not intended for original photogra phy, but necessary to complete the production process. LATENT IMAGE: Invisible image in exposed, undeveloped film; results from exposure to light. LATENT IMAGE EDGE NUMBERING: Images placed on the edge of film products in manufacturing that become visible after development.
149
LATITUDE: In a photographic process, the range of exposure over which substantially correct reproduction is obtained. When the process is rep resented by an H & D curve, the latitude is the projection on the expo sure axis of that part of the curve which approximates a straight line within the tolerance permitted for the purpose at hand. LAYBACK: Transferring the finished audio track back to the master video tape. LAYOUT: A detailed drawing of a shot in which background elements, stag ing of the action, and camera moves are carefully worked out and plot ted; the stage of production in which these are determined. See also scene planner. LEADER: Any film or strip of material used for threading a motion picture machine. Leader may consist of short lengths of blank film attached to the ends of a print to protect the print from damage during the threading of a projector, or it may be a long length of any kind of film which is used to establish the film path in a processing machine before the use of the machine for processing film. LENS: An optical device designed to produce an image on a screen, on a camera film, and in a variety of optical instruments. Also used to con verge, diverge or otherwise control light rays in applications not involv ing images. LIGHT: The main illumination of the subject. LIGHT AXIS: An imaginary line running exactly through the center of intensity of a light. LIGHT BALANCING FILTER: Makes minor color balance adjustments to the light reaching the film. LIGHT FILTER: A lightabsorbing transparent sheet, commonly consisting of colored glass or dyed gelatin that is placed in an optical system to control the spectral quality, color, or intensity of the light passing a given plane. LIGHT INTENSITY: Degree of light, per unit, falling on subject; usually expressed in footcandles. LIGHT METER: An electrical exposure meter for measuring light intensity. LIGHT METERS: See EXPOSURE METERS. LIGHT OUTPUT: The maximum power or energy delivered by a given light: concentrated by a spotlight, or spread out by a floodlight. 150
LIGHT PIPING: Fog caused by light striking the edge of film and traveling along the base to expose the emulsion inside the magazine or roll. LIGHTING BROAD LIGHTING: The key light illuminates fully the side of the face turned toward the camera. LIGHTING SHORT LIGHTING: The key light illuminates fully the "short" side of the face that is turned away from the camera. LIGHTING RATIO: The ratio of the intensity of key and fill lights to fill light alone. LIGHT VALVE: Device for controlling intensity and color quality of light on additive prints. LIP SYNC: Simultaneous precise recording of image and sound so that the sound appears to be accurately superimposed on the image, especially if a person is speaking toward the camera. LIQUID GATE: A printing system in which the original is immersed in a suitable liquid at the moment of exposure in order to reduce the effect of surface scratches and abrasions. LIVEACTION: The filming or videotaping of staged or documentary scenes of people, props and locations. LONG PITCH: Perforation type used on print films; slightly greater than perforations on originals films to prevent slippage during printing. LONG SHOT (LS): The photographing of a scene or action from a distance or a wide angle of view so that a large area of the setting appears on a frame of film, and the scene or objects appear quite small. LONGITUDINAL SCRATCHES: Scratches running along the length of film. LOOP (continuous film): A section of film spliced endtoend for use in printing, testing, dubbing, etc. LOOP (projector or camera): The path in which the film is formed to allow the film to travel intermittently through the gate. LOW KEY: A scene is reproduced in a low key if the tone range of the reproduction is largely in the high density portion of the H & D scale of the process. LTC (LONGITUDINAL TIME CODE): Time code recorded on one of the audio channels of video tape. Requires tape movement to read. (See also VITC) 151
LUBRICATION: To reduce friction, required on processed print film for optimum transport and projection life. LUMEN: The measure of luminous flux (the rate at which light pulses are emitted or received). For instance, one candela of light covering a square foot of surface. See FOOTLAMBERT. LUMINANCE: The measured value of brightness; reflected light measure on motion picture screens as footlamberts or candelas per square meter. LUX: Metric measure of illumination approximately equal to 10 footcandles (1 lux = 10.764 fc). MACHINE SPEED: The rate at which film moves through the processor, expressed in feet or meters per minute. MAGAZINE (projector): Enclosures on a motionpicture projector which holds the reels of film. MAGAZINE TAKEUP (United Kingdom uses the term spool box): The device which winds up the film after photography (in a camera), copy ing (in a printer), and after projection (in projection). MAGENTA: Purplish color; complementary to green or the minusgreen subtractive primary used in the threecolor process. Magenta light results when red and blue light overlap. MAGIC LANTERN: The first projection device, invented in the 17th Century by Athanasius Kircher, consisting of a metal box with a hole in one side covered by a lens; an image painted on a glass slide placed behind the lens is projected by means of a lamp inside the box. MAGNETIC DISK: A storage format for digital information used in com puters and other new technologies, and read by a magnetic disk drive. MAGNETIC HEAD CLUSTER: The component in a 35 mm magnetic sound head that contains the four magnetic heads used to play back the four separate magnetic tracks on a release print. In 70 mm applications, the cluster holds six magnetic heads. MAGNETIC SOUND: Sound derived from an electronic audio signal recorded on a magnetic oxide stripe or on fullcoated magnetic tape. MAGNETIC SOUND HEAD: The magnetic sound reproducer installed above the projector head but below the supply reel support arm or mag azine. MAGNETIC STRIPING: The application of magnetic material on motion picture film intended for the recording of sound. 152
MAGNETIC TAPE / MAGNETIC FILM: Usually 1/4inch plastic audio tape that has been coated with particles that can be magnetized. As used on tape recorders. In film use, it is also used in various formats compati ble with super 8, 16mm, 35mm and 70 mm films. MAGNETIC TRACK: Linear path of magnetically recorded audio signal on a magnetic film stripe or tape. The number of "mag tracks" can vary from one to six, depending on the picture format. MAGOPTICAL: Sound track with an optical track and one or more magnet ic tracks. MAGOPTICAL PRINT: Composite release print that contains both optical and magnetic sound tracks. MAKEUP TABLE: A film handling unit that is one component of a platter system. It is used to assemble (makeup) the individual shipping reels into one large film roll on a platter for uninterrupted projection. See Breakdown table. MALTESE CROSS: See Geneva movement. MANUFACTURER IDENTIFICATION CODE: Letter which identifies film manufacture. K = Eastman Kodak Company. MASKING: Restricting the size of a projected image on a screen by the use of black borders around the screen. Also the restriction in size of any projected image or photographic print by the use of undercut aperture plates or masks and borders. MASTER POSITIVE: Timed print made from a negative original and from which a duplicate negative is made. MASTER: The final negativereversal positive or intermediate film from which subsequent prints are made. MASTER SHOT: Usually a long shot in which all action in a scene takes place. Action is repeated for the MS and CU which may be cut into the scene. MATCH FRAME EDIT: An edit in which the source and record tapes pick up exactly where they left off. Often used to extend a previous edit. Also called a 'tacking edit". MATCHING CHECK SYMBOLS: Two (35mm) or four (16mm) randomly selected and placed symbols designed as an extra matching check. To use: after matching key number and checking picture, verify that same symbols are located in same position on both the workprint and the neg ative. 153
MATTE: An opaque outline which limits the exposed area of a picture, either as a cutout object in front of the camera or as a silhouette on another strip of film. MAXIMUM DENSITY (DMAX): Portion of the shoulder of the character istic curve where further increases in exposure on negative film or decreases in exposure on reversal film will produce no increase in den sity. MECHANICAL SPECIFICATIONS: The physical characteristics of a process that are designed to produce optimum results when used with specific film and chemical combinations. These include temperature, solution immersion times, replenisher rates, recirculation pump rates, filtration, agitation levels and other pertinent information. MEDIUM SHOT: A scene that is photographed from a medium distance so that the full figure of the subject fills an entire frame. METRECANDLE: Unit of illuminance. The light received at a point one metre away from a point light source having an intensity of one candela (formerly candle). MGM CAMERA 65: A motion picture production method developed at the MGM Studios using a 65 mm negative with an image height of five per forations and a horizontal compression ratio of 1.33:1. A 65 mm or 70 mm contact print could be shown on an appropriate 70 mm projector equipped with a 1.33:1 anamoiphic lens. Using special reduction print ing techniques, 35 mm prints could be made for CinemaScopetype pre sentations. MIDFOOT KEY NUMBER: Full key number plus bar code, including 32 perforation (35mm) offset, positioned halfway between each footage number. Will help identify short scenes without a key number. Uses a smaller type size to distinguish from onefoot key numbers. Use a mag nifying glass to read it easily. MINIMUM DENSITY (DMIN): Constantdensity area in the tone of the characteristic curve where less exposure on negative film or more expo sure on reversal film will produce no reduction in density. Sometimes called base plus fog in blackandwhite film. MIX: To combine the various sound tracksdialogue, music, sound effects into a single track. MIXING: The combining of several sound sources into one. MODELING: In computer graphics, the process of plotting the locations of the points that make up the dimensions of an object in three dimensional space. 154
MODULATION TRANSFER CURVE: Indicates the ability of a film to record fine detail. The curve results when light transmission is mea sured with lines that are successively more closely spaced. MOTORBOATING: The distracting sound heard when the film becomes misaligned over the sound drum and causes the sound scanning beam to "read" the film perforations instead of the sound track. MOVIOLA: A trademarked name for a machine with a small rearprojection screen and the capacity to play back several sound tracks. Used in edit ing and for reviewing portions of the film during production. Also used to synchronize or interlock picture and sound track in editing. Newer devices called "flatbed viewers" are slowly replacing the upright Moviolas. MULTIPASS: To expose the same piece of film two or more times during filming, usually to produce semitransparent effects, such as clouds or shadows. MULTIPLANE CAMERA: A special animation stand developed at the Disney studio and first used in The Old Mill in 1937. The background artwork is divided into foreground, middle, and distant elements and painted on sheets of glass placed several inches apart. During trucking or panning moves, the background elements move in relation to each other, creating an illusion of realistic depth and perspective. MULTIPLEXER: Device or circuit used for mixing television signals to a single video recorder. MUTOSCOPE: A viewing machine, manufactured in 1895 by the American Mutoscope Company, which used the "flip book" principle to create the illusion of movement. It contained a series of continuous photographs arranged on a horizontal axis. A coin was dropped into the machine to operate the handcrank that moved the pictures rapidly and created the illusion of movement. NARRATION: The offscreen commentary for a film; often referred to as "voiceover." NEGATIVE: The term "negative" is used to designate any of the following (in either blackandwhite or color): (1) The raw stock specifically designed for negative images. (2) the negative image. (3) Negative raw stock that has been exposed but has not been processed. (4) Processed film bearing a negative image. NEGATIVE FILM: Produces a negative image (black is white, white is black, and colors appear as complementaries).
155
NEGATIVE IMAGE: A photographic image in which the values of light and shade of the original photographed subject are represented in inverse order. Note: In a negative image, light objects of the original subject are represented by high densities and dark objects are represent ed by low densities. In a color negative, colors are represented by their complementary color. NEGATIVEPOSITIVE PROCESS: Photographic process in which a posi tive image is obtained by development of a latent image made by print ing a negative. NEGATIVE TIMING (Negative Grading): The selection of the appropriate printing lights for the printing process. NEGATIVETYPE PERFORATIONS: A generic term for the Bell and Howell type perforation. NEUTRALDENSITY FILTERS: Used to reduce the intensity of light read ing the film without affecting colors. NEUTRAL TEST CARD: A commercially prepared card: One side has a neutral 18percent reflection that has the appearance of medium gray .The other side has a neutral reflection of 90percent and has the visual appearance of stark white. NEWTON'S RINGS: Fuzzy, faintly colored lines in the projected image caused by high or uneven printer gate pressure. NITRATE FILM: A highly flammable motion picture film that has not been domestically manufactured since around 1950. It is still present in large quantities in storage vaults and archives and must be very carefully stored to prevent spontaneous combustion, explosions, or other forms of destruction (perhaps your destruction)! NOISE: Unwanted sound in an audio pickup. NOISE REDUCTION: Process of reducing inherent audio system noises by the use of special electronic circuitry. See DOLBY. NOMOGRAPH: For calculating the effect of a filter on color temperature. NONDROP FRAME: A type of SMPTE time code that continuously counts a full 30 frames per second. As a result, nondrop, frametime code does not match real time. (See also Drop Frame) NONSYNC SOUND: In theatrical projection, the amplifier channel selector position used when playing record or tape music during openings, inter missions, and closing. 156
NOTCHING: Practice of making a "V" cut to remove damaged perforations rather than removing the damage and making a splice. Not recommend ed, as it weakens the film even more. NTSC (NATIONAL TELEVISION STANDARDS COMMITTEE: Committee that established the color transmission system used in the U.S. and some other countries. Also used to indicate the system itself consisting of 525 lines of information, scanned at a rate of approximate ly 30 frames per second. OFFLINE EDITING: The process of creatively assembling the elements of a production, to communicate the appropriate message or story, and/or calculating the order, timing and pace with userfriendly equipment such as film, 3/4" videotape or nonlinear computer editing systems. ONETOONE PRINTING: Optical printing of the images which are repro duced to the same size. ONLINE EDITING: Final editing or assemble using the original master tapes to produce a finished program ready for distribution. Usually pre ceded by offline editing. In some cases, programs go directly to the on line editing suite. Usually associated with highquality computer editing and digital effects. OPACITY: Measurement of the amount of light that does not pass through a film or filter. OPAQUE: Of sufficient density so that all incident of light is completely absorbed (the opposite of transparent). OPAQUING: Another term for cel painting, used primarily in the eastern United States; a painter is referred to as an Opaquer. OPTICAL EFFECTS: Trick shots prepared by the use of an optical printer in the laboratory, especially fades and dissolves. OPTICAL PRINTER: Used when image size of the print film is different from the image size of the preprint film. Also used when effects such as skip frames, blowups, zooms, and mattes are included. OPTICAL SOUND: System in which the photographic (optical) sound track on a film is scanned by a horizontal slit beam of light that modulates a photoelectric cell. The voltages generated by the cell produce audio sig nals that are amplified to operate screen speakers. OPTICAL TRACK: Sound track in which the sound record takes the form of density variations (variable density track) or width variations (variable area track) in a photographic image. 157
OPTIMUM PRINT DENSITY:The desired screen quality. ORIGINAL: An initial photographic image, or sound recordingwhether photographic or magneticas opposed to some stage of duplication thereof. ORIGINAL NEGATIVE: The negative originally exposed in a camera. ORTHOCHROMATIC (ORTHO) FILM: Film that is sensitive to only blue and green light. OUTTAKE: A take of a scene which is not used for printing or final assem bly in editing. OVERCOAT: A thin layer of clear or dyed gelatin sometimes applied on top of the emulsion surface of a film to act as a filter layer or to protect the emulsion from abrasion during exposure, processing and projection. OVEREXPOSURE: A condition in which too much light reaches the film, producing a dense negative or a washedout reversal. OVERLAP SPLICE: Any film splice in which one film end overlaps the over film end. OVERLAY:A technique in cel animation in which foreground elements of the setting are painted on a cel and placed over the characters to give an illusion of depth to the scene. PAD ROLLER: A roller designed to hold the film against a sprocket. PAINT SYSTEM ('PAINTBOX'): An electronic device to create images for television, consisting of a workstation with an electronic pen, and soft ware tools to 'paint', combine and manipulate images. PAINTBOX: Trade name of a computer graphics system manufactured by Quantel. Often used as a generic term to describe computer graphics systems. The forerunner of "Harry". PAL (PHASE ALTERNATION BY LINE): Color television system devel oped in Germany, and used by many European and other countries. PAL consists of 625 lines scanned at a rate of 25 frames per second. PAN: A camera move in which the camera appears to move horizontally or vertically, usually to follow the action or scan a scene. In animation, the effect is achieved by moving the artwork under the camera. PAN SHOT: Derived from "panoramic." A shot which encompasses a wider area than can be viewed by the camera at one time, and which will be scanned by the camera by means of panning. 158
PANAVISION 35: A 35 mm process using 35 mm negative film and pho tographed through a Panavision anamorphic lens with a compression of 2X. Contact 35 mm prints are compatible with anamorphic systems such as CinemaScope. PANCHROMATIC (PAN) FILM: Blackandwhite film which is sensitive to all colors in tones of about the same relative brightness as the human sees in the original scene. Film sensitive to all visible wavelengths. PARALLAX: In camera work, the viewfinder often is mounted with its optical axis at an appreciable distance from the optical axis of the cam era lens, commonly resulting in inadvertent positional errors in framing. PATH OF ACTION: The movement of a character through a scene; used in layout. PEAK DENSITY: Wavelength of maximum absorption. PENTHOUSE, PENTHOUSE HEAD: The popular names assigned to the magnetic sound head. See Magnetic sound head. PERFORATION DAMAGE: On inspection the perforations through a mag nifying glass you will find damage progressing from cracked, chipped or elongated holes to torn holes. PERFORATIONS: Regularly spaced and accurately shaped holed which are punched throughout the length of a motion picture film. These holes engage the teeth of various sprockets and pins by which the film is advanced and positioned as it travels through cameras, processing machines, and projectors. PERSISTENCE OF VISION: The ability of the eye to perceive a series of rapid still images as a single moving image by retaining each impres sion on the retina for a fraction of a second, thus overlapping the images. This phenomena makes it possible to see the sequential project ed images of a motion picture as lifelike continuous movement. PERSPECTA SOUND: A system of recording that produces a form of stereophonic reproduction by using a single optical sound track carrying three subaudible control tones that can shift the one track sound source to the left, center, or right speakers with the appropriate reproducing equipment. The system is compatible with normal single track sound reproducers. PHENAKISTISCOPE: An early animation device that uses a disc with sequential drawings around its border in front of a mirror to create the illusion of motion.
159
PHOTO CD: An optical disk which stores photographic images in a digital format. The images can be played back on a TV screen by means of a photo CD player, which also allows simple image manipulation. PHOTOCELL: An electronic device that, when modulated by visible light, produces electrical impulses that can be amplified to drive audio speak ers. PHOTOGRAPHIC SOUND TRACK: See OPTICAL TRACK. PHOTOMETER: An electrooptical device used to measure light intensity (a light meter). PIN: A component of a camera of printer mechanism that engages with a perforation to secure the film at the time of exposure, or to advance the film for the next exposure. PIN REGISTRATION: A film term relating to the steadiness of the image. For optical and filmto tape transfers, a pinregistered device holds each frame in position for a perfectly registered image, critical for creating multilayered special effects. PITCH: (1) That property of sound which is determined by the frequency of the sound waves. (2) Distance from the center of one perforation on a film to the next; or from one thread of a screw to the next; or from one curve of a spiral to the next. PIXEL('PICTURE ELEMENT'): The digital representation of the smallest area of a television picture, appearing as a tiny dot on the television screen. In a full color image, each pixel contains three components a combination of red, green and blue signals reflecting the trichromatic nature of human vision. The number of pixels in a complete picture dif fers from one system to another; the more pixels, the greater the resolu tion. PIX1LATION: A stop motion technique in which fullsized props and live actors are photographed framebyframe to achieve unusual effects of motion. POLALITE (3D): A threedimensional 35 mm presentation first introduced by UniversalInternational in which the two images necessary to pro duce the 3D effect were contained on the same film. The system simpli fied the 3D projection process and corrected most of the problems encountered with the two film/two projector systems although the spe cial polarizing glasses were still necessary. POLARIZING FILTER: Transparent material used to subdue reflections and control brightness of the sky. 160
POLYESTER: A name for polyethylene terephthalate developed by E.I. Dupont de Nemours & Co. (Inc.) A film base material exhibiting supe rior strength and tear characteristics. Cronar is the trade name for Dupont motion picture products; ESTAR Base is the trade name for Kodak products. POSITIVE FILM: Motion picture film designed and used primarily for the making of master positives or release prints. POSITIVE IMAGE: A photographic replica in which the values of light and shade of the original photographed subject are represented in their nat ural order. The light objects of the original subject are represented by low densities and the dark objects are represented by high densities. POSTPRODUCTION:The work done on a film once photography has been completed, such as editing, developing and printing, looping, etc. POSTS YNCHRONIZATION: The recording of the sound track after the picture has been completed. PREMIER SYSTEM: A Kodak digital image enhancement system used to create and manipulate still photographic images at extremely high reso lution, suitable for print reproduction. PRESYNCHRONIZATION: The recording of the sound track before any production has begun, so that action can be synchronized when the film is exposed with the prerecorded sound. PRIMARY COLOR: One of the light colorsblue, red, or greenthat can be mixed to form almost any color. PRINTER LIGHTS: On an additive printer, incremental steps. PRINTER POINTS: An increment of lightintensity change. PRINT FILM: Film designed to carry positive images and sound tracks for projection. PRINTED EDGE NUMBERS: Edge numbers (usually yellow) placed on film at the laboratory by a printing machine. PRINTING: Copying motion picture images by exposure to light energy. PRINTING FLOWCHARTS: Diagram of printing sequences showing the steps that can be used to produce a projection print. PRINTING TAPE: A perforated strip or tape which provides information concerning the necessary changes of the printing light levels. 161
PROCESSING: Procedure during which exposed film is developed, fixed, and washed to produce either a negative or a positive image. PROCESS SCREEN PHOTOGRAPHY: The filming or videotaping of actors, props, or objects in front of a bluescreen (or greenscreen). In postproduction, the blue or green is replaced by another element, such as a background, using digital or optical special effects techniques. PROCESSING TIME: The amount of time it takes for a computer to process data. PRODUCER: The administrative head of the film, usually responsible for budget, staff, legal contracts, distribution, scheduling, etc. PRODUCTION: The general term used to describe the process involved in making all the original material that is the basis for the finished motion picture. Loosely, the completed film. PRODUCTION SUPERVISOR: An assistant to the producer, in charge of routine administrative duties. PROJECTION: The process of presenting a film by optical means and trans mitted light for either visual or aural review, or both. PROJECTION SPEED: The rate at which the film moves through the projec tor; twentyfour frames per second is the standard for all sound films. PROTECTIVE LEADER: A section of unexposed film attached to the beginning and/or end of a reel of film. PROTECTIVE MASTER: A master positive from which a dupe negative can be made if the original is damaged. PROUD EDGES: One or two convolution of film that protrude above the smooth surface of a firmly wound roll of film and are susceptible to damage. PULLDOWN CLAW: The metallic finger which advances the film one frame between exposure cycles. PUSH PROCESSING: A means of increasing the exposure index of film. R190 SPOOL: 4.940 outside diameter metal camera spool. Square hole with single keyway, two offset round drive holes, one elliptical hole in both flanges. Side 1 and side 2 markings. For 200 foot 16mm film loads. R90 SPOOL: 3.615 inch outside diameter metal camera spool. Square hole with single keyway in both flanges, with center hole aligned on both flanges for 100 foot film loads. Used in 16mm spoolloading cameras. 162
RACK: A frame carrying film in a processing machine. RACKOVER: A method of checking the precise center of the camera's field, in which the body of the camera is temporarily shifted to one side to allow the camera operator to look through a special viewfinder with cross hairs; the camera is shifted back into position for shooting to con tinue. Rackovers are often used to check the accuracy of offcenter shots. RASTER: The lines forming the scanning pattern of a television system. Scanned are comprising the active portion of a video signal displayed on a cathode ray tube (CRT). RAW STOCK: Unexposed and unprocessed motion picture film; includes camera original, laboratory intermediate, duplicating, and releaseprint stocks. REAL TIME: The instantaneous response of a computer or device to instruc tions: the normal viewing time of any film or videotape program. RECIPROCITY LAW: Expressed by (H)=Et, where E is the light intensity, and T is time. When E or T are varied to the extreme, an unsatisfactory exposure can result. RECOMMENDED PRACTICE: An SMPTE engineering committee recom mendation specifying good technical practice for some aspect of film or television. RECTIFIER: An electronic device designed to convert a current into the dc current necessary for operating carbon arcs, xenon arcs, exciter lamps, etc. REDUCTION PRINT: Print made from a largergauge film. REDUCTION PRINTING: Making a copy of a film original on smaller for mat raw stock by optical printing; for example, printing a 35 mm origi nal onto 16 mm stock for use in libraries, etc. REEL BAND: A stiff paper strip with a string loop tie that contains the release print number, title, and reel number and is used to keep the film snug on the shipping reel. REFLECTANCE: The brightness reflected from a surface such as a motion picture screen. See LUMINANCE. REFLECTOR: Any surface that reflects light. Reflectors can be constructed of cardboard, metal, cloth, or other material. In motion picture projec tion, primarily the lamphouse mirror and the screen. See MIRROR. 163
REFRACTION: The change of direction (deflection) of a light ray or energy wave from a straight line as it passes obliquely from one medium (such as air) to another (such as glass) in which its velocity is different. REJUVENATION: A process offered by some laboratories whereby a dam aged and dirty print can be rendered usable for further projection. RELEASE NEGATIVE: Duplicate negative or color reversal intermediate from which release prints are made. RELEASE PRINT: In a motion picture processing laboratory, any of numer ous duplicate prints of a subject made for general theater distribution. RELIEF IMAGE: The slightly dimensional image that can sometimes be seen on the emulsion side of a color print film viewed under a glancing light reflected towards the observer. REMJET BACKING: Antihalation backing used on certain films. Rem jet is softened and removed at the start of processing. RENDERING: The simulation of light on threedimensional objects; deter mining an object's surface characteristics, such as color and texture. RESOLUTION: The capacity of a medium to capture and playback distinctly fine details. Film is a high resolution storage medium; current video tape formats are low resolution mediums. Computers can perform at a wide range of resolutions, from the lowest to the highest, depending on hardware and software capabilities, and are therefore considered resolu tion independent. RESOLVING POWER: Ability of a photographic emulsion or an optical system to reproduce fine detail in the film image and on the screen. RETICULATION: The formation of a coarse, crackled surface on the emul sion coating of a film during improper processing. If some process solu tion is too hot or too alkaline, it may cause excessive swelling of the emulsion and this swollen gelatin may fail to dry down as a smooth homogeneous layer. REVERSAL FILM: Film that processes to a positive image after exposure in a camera, or in a printer to produce another positive film. REVERSAL INTERMEDIATE: Firstgeneration duplicate that is reversed to produce the same kind of image (negative or positive) as the original; used for printing.
164
REVERSAL PROCESS: Any photographic process in which an image is produced by secondary development of the silver halides grains that remain after the latent image has been changed to silver by primary development and destroyed by a chemical bleach. In the case of film exposed in a camera, the first developer changes the latent image to a negative silver image. This is destroyed by a bleach and the remaining silver halides is converted to a positive image by a second developer. The bleached silver and any traces of halides may now be removed with hypo. REVERSE ANAMORPHIC: An optical device which, when placed in front of a prime lens, reduces the size of the projected anamorphic image rather than magnifies it, as with a normal anamorphic attachment. This feature allows the use of short focallength prime lenses with larger apertures resulting in added screen luminance of up to 40 percent. See Anamorphic lens. REWIND: An automatic console or set of bench mounted spindles used to wind film from reeltoreel. REWINDING: The process of winding the film from the takeup reel to the supply reel so that the head end, or start of the reel, is on the outside. If there are no identifying leaders on the film, upsidedown images will signify the head end. RGB: Red green & blue, the primary color components of the additive color system used in color television. RIPPLE: Automatic updating of an EDL following a length altering edit. "Ripple the list." RMS: RootMeanSquare. This mathematical term is used to characterize deviations from a mean value. The term "standard deviation", which is synonymous, is also used. RMS GRANULARITY: Standard deviation of randomdensity fluctuations for a particular film. ROPING: Continuous sprocket tooth indentation along the length of the film; caused by a bad splice or other damage that forces the film to ride off the sprocket. ROTATION:A camera move in which the camera is moved in a complete circle to give a spinning effect in the film. A partial rotation is called a Tilt.
165
ROTOSCOPE: A device patented by Max Fleischer in 1917, that projects liveaction film, one frame at a time, onto a small screen from the rear. Drawing paper is placed over the screen allowing the animators to trace the liveaction images as a guide in capturing complicated movements. ROUGH CUT: Preliminary stage in film editing, in which shots, scenes, and sequences are laid out in an approximate relationship, without detailed attention to the individual cutting points. ROUGHS:The animators' original drawings, which are usually broad and sketchy, rather than finished drawings, and which are refined by the cleanup artist. RP40: The recommended practice sponsored by SMPTE titled, "Specifications for 35 mm Projector Alignment and Screen Image Quality Test Film." Also, the name usually referred to by projectionists for the test films made to these specifications and available from SMPTE as Projector Alignment and Image Quality Test Film, 351Q200. RP82: 16 mm version of above, except test film is identified as 16PA100. Also available from SMPTE. RS232: Electronic Industries Association (EIA) standard for serial data communications. S83 SPOOL: 3.657 inch outside diameter metal camera spool. Square holes with single keyway in both flanges. Center hole aligned on both flanges. For 100 foot 35mm camera negative film. SAFELIGHT: A darkroom light fitted with a filter to absorb light rays to which film is sensitive. "S" BENDS: Kinks in the film layers caused by pulling the end of the film on a loose roll in order to tighten the roll. Especially damaging to film containing oil deposits since no slippage is possible (oil deposits cause film to stick). SAFETY BASE: Film base that is fireresistant or slowburning as defined by ANSI PH1.25 and PH22.31, and by various fire codes. Acetatebase film and polyesterbase film meet safetyfilm standards. SAFETY FILM: A photographic film whose base is fire resistant or slow burning as defined by ANSI document PH1.25, PH22.21, and by vari ous fire codes. At the present time, the terms "safety base film," "acetate base film" and "polyester base film" are synonymous with "safety film." SAMPLING: The process of determining the best color combinations that represent an original image or desired effect. 166
SATURATION: Term used to describe color brilliance or purity. When color film images are projected at the proper brightness and without interference from stray light, colors that appear bright, deep, rich, and undiluted are said to be "saturated." SATURATION BOOKING: The simultaneous availability and showing of a new feature release in all the major theaters in the country. Such a release can involve more than 1,000 new prints. SATURDAY MORNING TELEVISION: A term which has its roots in the childoriented, limited animation cartoon shows that began to dominate this time slot in the 1950's, but has come to stand for this genre of massproduced animation. SCANNER: A device for scanning images and converting them into an elec tronic signal in a standard video format. SCANNING BEAM: A collimated narrow slit (0.1 mm or less) of light that scans the optical sound track of a motion picture film. SCENE PLANNER: In studio animation, the person who works with the director and storyboard artist to do detailed drawings of the scene, indi cating the path of action, background elements, camera moves, etc. Also known as a Layout Artist. See LAYOUT. SCENE: A segment of a film that depicts a single situation or incident. "SCOPE": A diminutive term used to describe any anamorphic projection system or film. See CINEMASCOPE. SCRATCHES: nonphotographic blemishes on the film emulsion or base. SCRIM: A translucent material that makes hard light appear more diffuse, or reduces, like a screen, the intensity of the light without changing the character of it. SCRIPT: The text of a film, giving dialogue, action, staging, camera moves, etc. SECAM(SYSTEM ELECTRONIQUE POUR COLOUR A VEX): The color television system developed in France, and used there and in most of the former communistblock countries and a few other areas including parts of Africa. SENSITIVITY: Degree of responsiveness of a film to light.
167
SENSITOMETER: An instrument with which a photographic emulsion is given a graduated series of exposures to light of controlled spectral quality, intensity, and duration. Depending upon whether the exposures vary in brightness or duration, the instrument may be called an intensity scale or a time scale sensitometer. SENSITOMETRIC CURVE: See Characteristic Curve. SENSITOMETRY: Study of the response of photographic emulsions to light. SEPARATION LIGHT: A light that helps define the outline of a subject, thereby separating it from the background. Also called edge light, top light, rim light, backlight, hair light, skimmer, or kicker. SEPARATION MASTERS: Three separate blackandwhite master positives made from one color negative; one contains the red record, another the green record, and the third the blue record. SEQUENCE: A group of related scenes in a film that combine to tell a par ticular portion of the story, and which are usually set in the same loca tion or time span. SET: Derived from "setting." The prepared stage on which the action for threedimensional animation takes place. A set may be as simple as a plain tabletop, or as elaborate as props and decoration can make it. SHADOW LIGHT: See FILL LIGHT. SHARPNESS: Visual sensation of the abruptness of an edge. Clarity. SHORELINE: Fuzzy lines or contours around the perforations in print film; caused by nonuniform drying. SHORT: The term usually refers to the cartoons made in the Hollywood stu dios during the 1930's, 1940's, and 1950's, which ran between 6 and 7 minutes long. Today, shorts range from one and onehalf to over 20 minutes in length and cover a variety of styles and subjects. SHORT PITCH (see Perforation Pitch): The perforation pitch of a negative stock, which is somewhat shorter than the pitch of positive stock to avoid slippage in contact printing. SHOT: An unbroken filmed segment; the basic component of a scene.
168
SHOULDER: Highdensity portion of a characteristic curve in which the slope changes with constant changes in exposure. For negative films, slope decreases and further changes in exposure (log H) finally produce no increase in density because maximum density has been reached. For reversal films, slope increases. SHRINKAGE: Reduction in the dimensions of motionpicture film caused by loss of moisture, support plasticizers, and solvents, as well as heat, use, and age. SHUTTER: In theatrical projection, a twobladed rotating device used to interrupt the light source while the film is being pulled down into the projector gate. Once blade masks the pulldown while the other blade causes an additional light interruption increasing the flicker frequency to 48 cycles per second ... a level that is not objectionable to the view er at the recommended screen brightness of 16 footlamberts (55 cande las per square meter). SIBILANCE: Excessive amount of vocal hiss when consonants such as "s" are spoken. SILVER RECOVERY: Reclaiming the silver from processing solutions. Primarily from the Fix. SINGLEFRAME EXPOSURE: The exposure of one frame of motion pic ture film at a time, in the manner of still photography. Commonly used in animation and timelapse. SILVER HALIDES: Lightsensitive compound used in film emulsions. SINGLEPERFORATION FILM: Film with perforations along one edge only. SINGLESYSTEM SOUND: Sound on a magnetic or optical track that was recorded on the same strip of film on which the action was recorded. 16 MM FILM: Film 16 mm wide. May have single or double perforations. SKIP FRAME: An optical printing effect eliminating selected frames of the original scene to speed up the action. SKIVINGS: Fine threadlike particles found in the vicinity of the projector gate; caused by physical abrasion against a sharp burr or nick on a filmpath component. SLITTING: The act of cutting apart a film into narrower sizes of the required width.
169
SLOW IN/SLOW OUT: Refers to the fact that panning and trucking moves usually begin slowly, gradually attain their full speed, then slow to a stop, to avoid a sense of jerkiness in the movement. SLOW MOTION: The process of photographing a subject at a faster frame rate than used in projection, to expand the time element. SMPTE: Acronym for the Society of Motion Picture and Television Engineers. SMPTE TEST MATERIALS CATALOG: A comprehensive list of test materials used to check the performance of projectors, optical and mag netic sound systems, image quality and alignment, television color ref erence and test patterns, plus other helpful items such as the SMPTE Universal Leaders. SNAKE TRACK: A common name for a scanning beam test film used to check the uniformity of illumination across the scanning slit. SOFT: The opposite of "hard". (1) As applied to a photographic emulsion or developer, having a low contrast. (2) As applied to the lighting of a set, diffuse, giving a flat scene in which the brightness difference between highlights and shadows is small. SOFT LIGHT: Light made up of soft, scattered rays resulting in soft, less clearly defined shadows; also called diffuse light. SOUND APERTURE: See ACADEMY APERTURE. SOUND DRUM: A flat roller in the sound head designed to keep the film precisely positioned at the point where the scanning beam slit scans the sound track. Also called the scanning drum. SOUND EFFECTS (FOLEY): Sound from a source other than the tracks bearing synchronized dialogue, narration or music: sound effects com monly introduced into a master track in the rerecording step, usually with the idea of enhancing the illusion of reality. SOUND GATE: The gate used in an optical sound head, instead of a sound drum, to keep the film sound track precisely aligned on the scanning beam slit during sound reproduction. SOUND HEAD: The optical sound reproducer mounted beneath the projec tor head, but above the takeup reel support arm or magazine. SOUND NEGATIVE: The negative record of photographic sound recording.
170
SOUND POSITIVE: A positive print of the photographic sound recording. SOUND READER: A device used for playback of sound tracks, particularly during the editing procedure. SOUND RECORDER: Device that may use audio tape, magnetic film, or motionpicture film to record sound. SOUND SPROCKET: Any sprocket that pulls the film past the sound scan ning beam slit. SOUND STRIP: Narrow band of magnetic recording medium on a strip of film. SOUND TRACK: Photographic/optical sound track running lengthwise on 35 mm film adjacent to the edges of the picture frames and inside the perforations. SPARKLE: Printedin dirt that causes white dirt in the projected image. SPECIAL DISTRIBUTION: Range and proportion of wavelengths radiated by a particular illuminant. SPECIALDYEDENSITY CURVE: A graph: 1. of the total density of the three dye layers measured as a function of wavelengths, and 2. of the visual neutral densities of the combined layers similarly measured. SPECIAL EFFECT: A term broadly applied to any of numerous results obtained in the laboratory by combination and manipulation of one or more camera records to produce an imaginatively creative scene differ ent from what was in front of the main camera. The making of special effects may involve techniques such as double printing, fades, mattes, vignetting, etc. SPECTRAL INTEGRAL DENSITY: Density at a specific wavelength deter mined by a spectrophotometer. SPECTRAL OUTPUT: The range, intensity, and characteristics of wave lengths emanating from a light source. SPECTRAL RESPONSE: The measure of the ability to differentiate among wavelengths and characteristics emanating from a light source. The ability of a camera film to record various wavelengths (colors) of light. SPECTRAL SENSITIVITY: The relative sensitivity of a particular emulsion to specific bands of the spectrum within the films sensitivity range. Sometimes confused with Color Sensitivity. 171
SPECTRUM: Range of radiant energy within which the visible spectrumwith wavelengths of from 400 to 700 mm exists. SPECULAR: A term used to describe mirrorlike quality of a reflection or reflected light from a surface. Specular also can describe a hard or pointsurface light such as the sun, arc light, or any other light produc ing nearly parallel beams and hard shadows. SPECULAR DENSITY: Comparing only the transmitted light that is perpen dicular to the film plane with the normal incident light, analogous to optical printing and projection. SPEED: 1. Inherent sensitivity of an emulsion to light. Represented by a number derived from a films characteristic curve. 2.The largest lens opening (smallest fnumber) at which a lens can be set. A "fast" lens transmits more light and has a larger opening and better optics than a "slow" lens. SPLICE: Any type of cement or mechanical fastening by which two separate lengths of film are united endtoend so they function as a single piece of film when passing through a camera, film processing machine, or projector. SPLICER: A mechanical device arranged for holding film in alignment and with the correct sprocket hole interval during the various operations required in joining two pieces of film. It often includes a device for removing emulsion. SPLICING: The joining together of two or more pieces of film so that the joined film segments will pass through a projector, film processor, or camera without interruption. SPLICING TAPE: Tape designed to make overlap or butt splices without the need for film cement or mechanical fastener. Available in a variety of sizes, with or without perforations, and can be clear, translucent, or opaque orange. SPOOKING: Caused by loose winding of film that has considerable curl. SPOOL: A roll with flanges on which film is wound for general handling. SPOTLIGHT: A lighting unit, usually with a lens and shiny metal reflector that is capable of being focused; produces hard light. SPROCKET: A toothed wheel used to transport perforated motion picture film.
172
SQUASH AND STRETCH: An element of character animation which involves the exaggeration of the normal tendency of an object in motion to undergo a degree of distortion, lengthening as it travels, and com pressing as it stops. STABILIZATION: The influence of a magnetic flux in steadying the flow of electrons in a carbon arc. The action of a damping roller or other device in reducing wow and flutter in a soundhead. STAGING: The planning of how the action will take place. STAND:The entire photographing unit, including the compound, camera, and crane. STANDARD FIELD: See FIELD. STATIC ELECTRICITY: Electric field that is present primarily due to the presence of electrical charges on materials. STEEL FILM: A steel tape, precisely dimensioned and perforated, used to align motion picture equipment. STEP: An exposure increase or decrease, usually by a factor of 2. The same as "Stop", except stop specifically refers to lens aperture. A patch of a step tablet used for sensitometer exposures, as in "21step tablet." STEPCONTACT PRINTER: Contact printer in which the film being copied and the raw stock are advanced intermittently by frame; exposure occurs only when both are stationary. STEP PRINTER: Contact or optical printer in which each frame of the nega tive and raw stock is stationary at the time of exposure. STEREOPHONIC: Sound recording and reproduction with multiple micro phones and speakers, each of which has its own separate track; designed to simulate the actual sound and to achieve a threedimensional effect. STILL STORE: Device which stores individual video frames, either in ana log or digital form, allowing extremely fast access time. STOCK: General term for motion picture film, particularly before exposure. STOP: The relationship between the focal length of a lens and the effective diameter of its aperture. An adjustable iris diaphragm permits any ordi nary photographic lens to be used at any stop within its range. Sometimes used synonymously with fnumber as in "fstop". A unit of exposure change.
173
STOP DOWN: To decrease the diameter of the lightadmitting orifice of a lens by adjustment of an iris diaphragm. STOP FRAME (HOLD FRAME): An optical printing effect in which a sin gleframe image is repeated to appear stationary when projected. Also, camera exposure made one frame at a time rather than by continuous running. STOP MOTION: An animation method whereby apparent motion of objects is obtained on the film by exposing single frames and moving the object to simulate continuous motion. STORYBOARD: A series of small consecutive drawings with accompany ing captionlike descriptions of the action and sound, which are arranged comicstrip fashion and used to plan a film. The drawings are frequently tacked to corkboards so that individual drawings can be added or changed in the course of development. Invented at the Disney studio, the technique is now widely used for live action films and com mercials, as well as animation. STRAIGHTLINE REGION: Portion of characteristic curve where slope does not change because the rate of density for a given log exposure change is constant or linear. STRAY LIGHT: Any light that does not contribute to the purpose for which it was intended. In theatrical projection, all of the nonimageproducing light hitting the screen. STRIP: Part of a wide roll of manufactured film slit strips final width for motion picture use. STRIPE, MAGNETIC: Narrow band(s) of magnetic oxide usually coated toward the edges of the base side of motion picture film for accepting audio signal recordings in the form of magnetic impulses. SUBBING LAYER: Adhesive layer that binds film emulsion to the base. SUBTRACTIVE COLOR: The formation of colors by the removal of select ed portions of the white light spectrum by transparent filters or dye images. SUBTRACTIVE PROCESS: Photographic process that uses one or more subtractive primarycyan, magenta, and yellowto control red, green, and blue light. SUNLIGHT: Light reaching the observer directly from the sun. To be distin guished from Daylight and Skylight which include indirect light from clouds and refract the atmosphere. 174
SUPER PANAVISION: Similar to Panavision 35, but photographed flat in 65 mm. The 70 mm prints produce and aspect ratio of 2.25:1 with 4 channel sound and a ratio of 2:1 with 6channel sound. SUPERSCOPE: A 35 mm anamorphic release print system adopted by RKO Radio Pictures that produced a screen image with an aspect ratio of 2:1 or 2.35:1 when projected with a normal anamorphic lens. The original camera negative was photographed flat, but special printing produced the anamorphic print. SUPPLY REEL: The reel holding the film before it is projected in a projec tor. SURROUND CHANNEL: The specific sound channel in a sound reproduc tion system directing audio signals to speakers placed at the sides and at the rear of the auditorium to provide the added realism of surrounding area sounds. SURROUND SPEAKERS: Speakers placed at the sides and at the rear of an auditorium to increase the realism of a stereophonic presentation, or to produce other special effects. SWEETING: Audio post production, at which time audio problems are cor rected. Music, narration and sound effects are mixed with original sound elements. SWELL: The increase in motion picture film dimensions caused by the absorption of moisture during storage and use under high humidity con ditions. Extreme humidity conditions and subsequent swelling of the film aggravates the abrasion susceptibility of the film surfaces. SWITCHER: Device with a series of input selectors that permits one or more selected inputs to be sent out on the program line. SYNCHRONIZER: A mechanism employing a common rotary shaft that has sprockets which, by engaging perforations in the film, pass corre sponding lengths of picture and sound films simultaneously, thus effec tively keeping the two (or more) films in synchronism during the edit ing process. SYNC PULSE: Inaudible timing reference recorded on the magnetic tape used in doublesystem recording. The source can be a generator in the camera cabled to the tape recorder, or an oscillating crystal in the recorder when the camera also has a crystal. When the sound is trans ferred to magnetic film for editing, a resolver reads the reference and ensures that the tape runs at the same speed as during shooting. In this way the magnetic workprint can be placed in sync with the images for which the original sound was recorded. 175
SYNCHRONIZATION: A picture record and a sound record are said to be "in sync" when they are placed relative to each other on a release print so that when they are projected the action will coincide precisely with the accompanying sound. See LIP SYNC. SYNCHRONIZE: Align sound and image precisely for editing, projection, and printing. TGRAIN EMULSION: Emulsion made up of tabletlike crystals rather than conventional silver halides crystals; produces highspeed films with fine grain. TSTOP: A lens marking which indicates the true light transmission of the lens at a given aperture instead of the approximate light transmission indicated by the conventional fstop marking. TAF: Telecine Analysis Film (TAF) is an objective tool for initial setup and centering of the controls on a telecine before you transfer images from film to video. TAIL ENDS, TAILS: The end of a film. The film must be rewound before projection if it is tails out. TAKE: When a particular scene is repeated and photographed more than once in an effort to get a perfect recording of some special action, each photographic record of the scene or of a repetition of the scene is known as a "take." For example, the seventh scene of a particular sequence might be photographed three times, and the resulting records would be called: Scene 7, Take 1; Scene 7, Take 2; and Scene 7, Take 3. TAKEUP REEL: The reel onto which the already projected film is wound up in a projector. TAPE SPLICE: Film splice made with special splicing tape applied to both sides of the film. TAPE SPLICER: Device designed for making film splices with special splic ing tape. Most use unperforated tape, and then punch perforations into the tape as the splice is made. TECHNICOLOR: The trade name of a threecolor imbibition process used to make release prints; no longer used in this country or Europe, but still being used commercially in China.
176
TECHNIRAMA: A 70 mm release print technique developed by Technicolor and printed from a horizontal double frame 35 mm negative with a 1.5:1 horizontal compression. The 35 mm reduction print image had a 1.33:1 compression ratio and produced a 2:1 aspect ratio when projected on equipment designed for CinemaScope. Some 70 mm prints were also available to be shown at a 2.2:1 ratio. TECHNISCOPE: A system designed to produce 35 mm anamorphic prints from a 35 mm negative having images approximately onehalf the height of regular negative images and produced by using a special one half frame (2 perforation) pulldown camera. During printing, the nega tive image was blown up to normal height and squeezed to normal print image width to produce a regular anamorphic print that provided a pro jected aspect ratio of 2.35:1. The system was designed primarily to con serve negative raw stock. TELECINE: A device for scanning motion picture film images and convert ing them to standard videotape. TENSION: The resistance to linear motion of the film caused by restraining forces such as tension pads, drive sprockets, takeup drive motors, springloaded guide rails, and the like, built into projectors, cameras, and other film handling equipment. THIN: As applied to a photographic image, having low density. As applied to the physical properties of film, thin base film materials provide for more film per given roll diameter. 35 MM FILM: Film 35 mm wide with four perforations on both edges of each frame. Image frame and soundtrack area lie inside the perfora tions. THREAD: To place a length of film through an assigned path in a projector, camera, or other film handling device. Also called lacing. 3D: The common term applied to threedimensional (stereoscopic) images projected on a screen or viewed as a print. There have been several sys tems shown in theaters but the discomfort attributed to the necessary eyewear, along with other equipment limitations has, more or less, rele gated the present systems to novelties. THROW: In theatrical projection, the distance from the projector aperture to the center of the screen. TIGHT WIND: Relating to film wound tightly on a core or reel to form a firm roll that can be handled and shipped safely without danger of cinch marks or other damage to the film.
177
TIME BASE CORRECTOR (TBC): An electronic device with memory and clocking circuits used to correct video signal instability during the play back of video tape material. TIMEFOG CURVE: Plot of the rate of fog growth against a series of devel opment times. TIMEGAMMA CURVE: A plot of the rate of gamma change over a series of development times. Used to determine optimum development time for blackandwhite negative or positive film. TIMELAPSE MOVIE: A movie that shows in a few minutes or a few sec onds, events that take hours or even days to occur; accomplished by exposing single frames of film at fixed intervals. TIMING: A laboratory process that involves balancing the color of a film to achieve consistency from scene to scene. Also includes adjusting expo sure settings in duplication. TITLE: The name or designation of a film. Also, any inscription contained in a film for the purpose of conveying information about the film, its message, or its story to the viewer. TODDAO: A flat, 70 mm print system developed by Magna Pictures Corporation and American Optical Company to produce a 2.2:1 screen image of high resolution, sharpness, and brightness. The print was made from a 65 mm negative exposed in a specially designed camera. The extra width of the print film was intended to provide room for the six magnetic sound tracks contained on four magnetic oxide stripes. Todd AO is considered the first commercially successful 70 mm film system and was introduced in 1955 with the release of Oklahoma. TOE: Bottom portion of the characteristic curve, where slope increases grad ually with constant changes in exposure. TONE: That degree of lightness or darkness in any given area of a print; also referred to a value. Cold toes (bluish) and warm tones (reddish) refer to the color of the image in both blackandwhite and color photographs. TRAILER: A length of film usually found on the end of each release print reel identifying subject, part, or reel number and containing several feet of projection leader. Also a short roll of film containing coming attrac tions or other messages of interest. TRANSITION: The passage from one episodic part to another. Usually, film transitions are accomplished rapidly and smoothly, without loss of audience orientation, and are consistent with the established mood of the film. 178
TRANSMITTANCE: Amount of incident light transmitted by a medium; commonly expressed as percent transmittance. TRAVEL GHOST: A condition that arises when the projector shutter is not properly timed. On the screen, light areas produce "ghosts" that extend above or below adjacent dark areas, depending on whether the shutter is late or early. See TIMING. TRAVELLING MATTE: A process shot in which foreground action is superimposed on a separately photographed background by optical printing. TRIANGLE: A threesided framework of wood or metal, designed to hold the three points of a tripod to limit their spread. TRIMS: Manual printer controls used for overall color correction. Also, unused portions of shots taken for a film; usually kept until the produc tion is complete. TRUCK:A camera move in which the camera seems to move toward (Truck In) or away from (Truck Out) the subject. The same effect is called a zoom in liveaction filmmaking. TRUCKING: To move a camera translationally in space as a shot proceeds, usually by means of a dolly or other vehicular camera support. The pur pose is to pace, and maintain image size of moving subjects. TUNGSTEN LIGHT: Light produced by an electrically heated filament, having a continuous spectral distribution. TWIST: An effect that is produced in new prints by loose winding of the film, emulsion side in, under dry air conditions. If the film is wound emulsion side out under the same conditions, the undulation do not alternate from one edge to the other but are directly opposite one anoth er. See EDGEWAVE. TYPE C: The SMPTE standard for the 1inch nonsegmented helical video tape recording format. TYPE K CORE: 3 inch outside diameter, 1 inch inside diameter plastic core. Used with 1000, 2000, 3000, and 4000 foot lengths of negative, sound and print films. TYPE T CORE: 2 inch outside diameter, 1 inch inside diameter plastic core, used with most 16mm films up to 400 feet. TYPE U CORE: 2 inch outside diameter, 1 inch inside diameter plastic core. Used with various length camera negative, sound and print films. 179
TYPE Y CORE: Similar to K but of heavier construction. Used for most color print films. TYPE Z CORE: 3 inch outside diameter, 1 inch inside diameter plastic core. Used with camera and print films in rolls longer than 400 feet. UMATIC: The trade name for the 3/4 inch videocassette system originally developed by Sony. Now established as the ANSI (American National Standards Institute) Type E video tape format. ULTIMATE: Trade name of a highquality special effects system similar in application to a chromakeyer. ULTRA PANAVISION: Similar to Super Panavision but the 65 mm nega tive has a compression ratio of 1.25:1 that can provide a potential aspect ratio of 2.75:1 on the screen. The 70 mm print is projected with an anamorphic lens having a 1.25 image spread thus producing an extremely large screen image. Reduction prints to 35 mm are compati ble with standard anamorphic systems. ULTRASONIC CLEANER: Device that transfers ultrasonic sound waves to a cleaning liquid or solvent that dislodges embedded dirt on objects immersed in it. ULTRAVIOLET LIGHT: Energy produced by the (invisible) part of the electromagnetic spectrum with wavelengths of 100 to 400 nanometers. Popularly known as "black light." UV radiation produces fluorescence in many materials. ULTRAVIOLET RADIATION: Radiation at the short wavelength end of the spectrum, not visible to the eye. It produces fluorescence in some mate rials. ULTRA VISION: A 35 mm custom system designed to provide a high defini tion and improved contrast film presentation on a slightly curved screen. Ultravision was designed as a complete system in which theater design was an integral part. Projectors, lenses, and lamphouses were also modified. UNDEREXPOSURE: A condition in which too little light reaches the film, producing a thin negative or a dark reversal or print. UNDERSCAN: Reducing the height and width of the picture on a video monitor so that the edges, and thus portions of the blanking, can be observed.
180
UNIVERSAL LEADER: A film projection leader, designed according to ANSI document PH22.55 for the current projection rate of 24 frames per second (1 1/2 feet per second), and recommended for use on all release prints. It was designed to replace the Academy leader originally conceived when the motion picture projection rate was 16 frames per second. UNSQUEEZED PRINT: A print in which the distorted image of an anamor phic negative has not been corrected for normal projection. UNSTEADINESS: An objectionable amount of vertical motion in the screen image. USER BITS: Portions of the scan lines in the vertical interval, above the active picture area, reserved for recording information of the user's choosing, e.g. Keykode numbers,SMPTE time code, etc. VALVE ROLLERS: A cluster of three or four small rollers located at the entrances of the film magazines and designed to prevent fire from reaching the film reels. Since nitrate prints are now quite rare, and are actually unlawful to use in some areas of the United States, use of valve rollers, or fire rollers, is no longer essential on domestic projection equipment. VARIABLE AREA SOUND TRACK: Photographic sound track consisting of one or more variablewidth transparent lines that run the length of a motionpicture film within the prescribed soundtrack area. The most common type of track. VARIABLEDENSITY SOUND TRACK: Photographic sound track that is constant in width but varies in density along the length of a motionpic ture film within the prescribed soundtrack area. No longer used in motionpicture productions. VECTOR SCOPE: A special oscilloscope used in television to set up and monitor color reproduction. VERTICAL INTERVAL: Indicates the vertical blanking period between each video field. Contains additional scan lines above the active picture areas into which nonpicture informationuser bitscan be recorded. VERTICAL SYNC: The synchronizing pulses used to define the end of one television field and the start of the nextoccurring at a rate of approxi mately 59.94Hz (color), and 60 Hz (black & white). VIDOSCOPE: A widescreen process compatible with CinemaScopetype presentations.
181
VIEWER: A mechanical and optical device designed to permit examination of an enlarged image of motion picture film during editing. VIEW FINDER: A registration device mounted near the top of the animation stand that allows the camera operator to check whether or not the cam era is trained on the center of the field. See RACKOVER. VIGNETTING: The partial masking, or blocking, of peripheral light rays either by intent, or by accident. In theatrical projection, the blockage of peripheral light rays in a projection lens due to a lens barrel that is too long, or to a lamphouse optical system that is not correctly matched to the limiting aperture of the projection lens. In photography, the inten tional masking of peripheral light rays to soften and enhance a photo graph. VISION MIXER: British term for video switcher. VISUAL DENSITY: Spectral Sensitivity of the receptor which approximates that of the human eye. VISTAVISION: System designed by Paramount Pictures to provide a sharp screen image with very high resolution. The 35 mm negative film passed through the camera horizontally and contained an image approx imately twice the size of a typical 35 mm printfilm image. During reduction printing, the negative image was reduced to normal print size, reducing negative grain and increasing sharpness and resolution. Normal projection aspect ratio was 1.85:1. VISTORAMA: A widescreen process compatible with CinemaScopetype presentations. VITC (VERTICAL INTERVAL TIME CODE): Time code that is recorded in the vertical blanking interval about the active picture area. Can be read from video tape in the "still" mode. VOICE ARTIST:An actor who performs the voices for the animated charac ters during a recording. VOICEOVER: See NARRATION. VOICEOVERNARRATION: A sound and picture shot relationship in which a narrator's voice accompanies picture action. WARPING: Synonymous with the misused term "buckle" when describing film distortions. These terms are too vague to be helpful in communica tion. WEAVE: Periodic sideways movement of the image as a result of mechani cal faults in camera, printer or projector. 182
WETGATE PRINTER: Printer in which the film passes through fluidfilled pads just before exposure. Released fluid temporarily fills film scratches with a solution that has the same refractive index as the film base, there by eliminating scratch refraction and ensuring that the scratches will not appear on the printed film. WIDESCREEN: General term for form of film presentation in which the pic ture shown has an aspect ration greater than 1.33:1. WILD: Picture or sound shot without synchronous relationship to the other. WINDING: Designation of the relationship of perforation and emulsion position for film as it leaves a spool or core. WINDOW DUB: A "burnedin window", usually on a video workprint, showing time code and Keykode numbers. Other windows can be added, e.g., running footage, audio time code, scenetake, date, etc. WIPE: Optical transition effect in which one image is replaced by another at a boundary edge moving in a selected pattern across the frame. WORKPRINT: Any picture or sound track print, usually a positive, intended for use in the editing process to establish through a series of trail cut tings the finished version of a film. The purpose is to preserve the orig inal intact (and undamaged) until the cutting points have been estab lished. WORKSTATION: The host computer for any user application; in digital special effects, the workstation allows the user to process images and interface with digital devices. XENON ARC: A short arc contained in a quartz envelope in which dc cur rent, flowing from the cathode to the anode, forms an arc in a positive (high pressure) atmosphere of xenon gas. The spectral distribution in the visible range closely resembles natural daylight. XENON BULB: The quartz envelope containing the two electrodes that pro duce an arc in a highpressure environment of xenon gas. XFR: Shorthand slang for "transfer." YELLOW: Minusblue subtractive primary used in the threecolor process. ZEROFRAME REFERENCE MARK: Dot which identifies the frame directly below as the zeroframe specified by both the humanreadable key number and the machinereadable bar code.
183
ZOETROPE: An early animation device that uses strips of sequential draw ings that are spun and viewed through slits in a rotating drum to create an illusion of motion. ZOOMIN: A continuous changing of the camera lens focal length, which gradually narrows down the area of the picture being photographed, giving the effect of continuously enlarging the subject. ZOOMOUT: A continuous changing of the camera lens focal length, which gradually enlarges the area being photographed, giving the effect of a continuously diminishing subject.
184
Motion Picture and Television Imaging EASTMAN KODAK COMPANY • ROCHESTER, NY 14650 Kodak, TGrain, Eastman, Ektachrome, Estar, Keykode, and Wratten are trademarks. Student Filmmaker's Handbook KODAK Publication No.
H19
Major Revision 795 Printed in U.S.A.